In multicellular organisms, cells use many kinds of extracellular molecules to send signals and communicate with one another. All signal molecules act as ligands and that bind to receptors expressed by their target cells, there is noticeable variation in the structure and function of the various types of molecules that play as signal transmitters. Cells communicate with each other via direct contact  juxtacrine signaling, paracrine signaling, and endocrine signaling. Cell signaling can be divided to be mechanical and biochemical based on the type of the signal. Some cell–cell communication requires direct cell–cell contact. Some cells can form gap junctions that connect their cytoplasm  to the cytoplasm of adjacent cells. In cardiac muscle, gap junctions between adjacent cells provides for action potential  propagation from the cardiac pacemaker region of the heart to spread and coordinately cause contraction of the heart.

Protein and intracellular signaling peptides generally are peptides and proteins which are involved in transmission of signals or signal transduction across the membrane of all cells. Signals in the form of second messengers, hormones, proteins and other biological molecules which are recognized by cell surface receptors that transfer their response to other intracellular signaling peptides and Protein like Transcriptor Factor. The broadly distributed monoaminergic neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) exerts its actions via 14 classes of receptor. In many signaling pathways, many type of factors have been isolated by molecular genetic studies and whole genome analysis.

Ample number of diseases is caused by defects in signaling pathways. The nature of these defects and how they are induced varies excessively. Pathogenic organisms and viruses, many of which can obstruct with signaling events, cause some of these defects. The thought of signalsome remodeling and disease provides a schema for considering how defects in signaling pathways can conclude in disease. Most of the severe diseases in humans, such as hypertension, diabetes and many forms of mental illness, look to appear from subtle phenotypic modifications of signaling pathways. 

Adhesion of cells is a prime factor of the architecture of many tissues. Cell adhesion is the process cells interact and attach to a  surface, substrate or another cell, mediated by interactions between molecules of the cell surface. Cell adhesion happens from the action of transmembrane glycoproteins, and these include selectins, integrins, syndecans and cadherins. Cellular adhesion is essential in maintaining multicellular structure. Cell adhesion includes like Genomic and Functional Screening. Cell adhesion is also essential for the pathogenesis of infectious organisms. Viruses also have adhesion molecules required for viral binding to host cells like in influenza virus. Dysfunction of cell-adhesion and cell-migration occurs during cancer metastasis.

The goal of research in signal transduction is to identify the functions of various signaling pathways in physiological and pathological states. Traditional techniques using biochemical, genetic or cell biological approaches have made crucial grants to our understanding of cellular signaling. However, the single-gene approach does not take into account the full complexity of cell signaling. With the connections of omics techniques, huge progress has been made in understanding signaling networks. Advanced approach of cell signaling includes protein profiling and phosphorylation profiling and in this section also has molecular profiling which includes genomics proteomics and post translation modifications. By the process of cell signaling pathways, HIV may be cured.

There are many treatments for cancer. The goal of any treatment is to remove cancerous cells to try to ensure cancer doesn’t return. It can be challenging because even if just one cancerous cells remains after treatment. A lot of experimental cancer treatments are also under development. Sometimes this can be proficient by surgery, radiotherapy, chemotherapy but the susceptibility of cancers to infect adjacent tissue or to spread to distant sites by microscopic metastasis usually limits its effectiveness. Biopsy is another option for cancer treatment.

It  is the use of ionizing radiation that means high doses of radiation to kill cancer cells and shrink tumors. It can be administered externally via external beam radiotherapy  or internally via brachytherapy. Radiation therapy kills malignant cells by the process of linear accelerator. High Precision Radiation Therapy techniques used for treatment such as 3D CRT, TBI, IMRT, IGRT, Stereotactic Radio surgery (SRS), Stereotactic Radiation Therapy (SRT) and VMAT to minimize damage to normal tissue. Radiation therapy may be used to treat approximate each type of solid tumor, comparing cancers of the brain, breast, cervix, larynx, liver, lung, pancreas, prostate or soft  tissue sarcomas.

Chemotherapy is a class of cancer treatment  that uses one or more anti-cancer drugs as part of a standardized chemotherapy regimen. Chemotherapy is one of the major categories of medical oncology that is devoted to pharmacotherapy. Chemotherapy is considered a systemic therapy. It means it may affect your entire body. Chemotherapy is one of the major categories of medical oncology.

It is a treatment of disease to suppress induces or enhances the immune response. Few types of immunotherapy are also sometimes called biologic therapy or biotherapy. Suppression immunotherapies is a part of this in which Immunosuppressive drugs help manage organ transplantation and autoimmune disease. Therapies such as granulocyte colony-stimulating factor, interferons,imiquimod and cellular membrane fractions from bacteria are licensed for medical use. Immunotherapy also includes the monoclonal antibodies, adoptive cell therapies and cancer vaccines. The unveiling of the sequence of the human genome, upgrading bioinformatics tools and optimized immunological analytical tools have made it possible to screen any given protein for immunogenic epitopes. Cancer immunotherapy introduces a diverse set of therapeutic strategies designed to induce the patient's own immune system to fight the tumor. Vaccines to generate specific immuneresponses in research of malignant melanoma and renal cell carcoma. Sipuleucel-T is a vaccine-like strategy is also used for prostate cancer Allogeneic hematopoietic stem cell transplantation  also a class of immunotherapy.

A stem cell transplant can be used to infuse healthy stem cells into the body to stimulate new bone marrow growth, suppress the disease, and decrease the possibility of a relapse. Stem cells can be found in the bone marrow, circulating blood and umbilical cord blood. CSCs are tumor forming in contrast to other non tumorigenic cancer cells. Such cells are hypothesized to endure in tumors as a distinct population and cause relapse and metastasis by giving rise to new tumors. For cancer stem cell therapy many models available like tumor propagation model, mechanistic and mathematical model and mathematical model is based on cell compartment method. CSCs include flurescence-activated cell sorting.

The analysis of cancer has undergone evolutionary changes as understanding of the underlying biological processes has risen. Tumor removal surgeries have been documented in ancient Egypt, hormone therapy and radiation therapy were advanced in the late 19th Century. Chemotherapy, immunotherapy and newer targeted therapies are products of the 20th century. External radiation and radiation implants under the radiation therapy. Common therapies include the  biologic therapies, targeted therapies, complementary and alternative therapy also.

Systems biology is the study of biological systems whose behavior cannot be diminished to the linear sum of their parts function. System biology does not accordingly include vast number of components or large datasets, like in genomics or connectomics, but usually requires quantitative modeling methods imitated from physics. This ability to design predictive, multiscale models to discover new biomarkers for disease, stratify patients based on unique genetic profiles, and target drugs and other treatments. Systems biology, creates the potential for entirely new kinds of analysis, and drives constant innovation in biology-based technology and computation. Computational biology is a main part of this field.