Cells can communicate by sending and receiving signals that travel through the body. Since these signals control critical processes like growth, metabolism, and immune defense, unraveling their biology could lead to development of therapies that harness their function. Several classes of cellular signaling molecules are described below. Utilize the table that follows to find your signals of interest, and discover a complete set of reagents for studying their biology, including recombinant proteins for stimulating cells, fluorophore-conjugated antibodies, and multiplex assays that simultaneously detect multiple analytes. 

Cytokines are a diverse set of signaling proteins that determine the movement, differentiation, and roles of immune cells. They are important for controlling the type of immune response that is mounted, and can cause abnormal immune activation or suppression if dysregulated. Types of cytokines include interferons, interleukins, chemokines, and colony-stimulating factors.

Chemokines are a type of cytokine that guide immune cells to their target destination. Recruitment of the proper cells to the right location is important for an effective immune response. For example, detection of an antigen at a specific site in the body leads to the production of a chemokine gradient that attracts cells like macrophages, dendritic cells, and T cells to that particular tissue.

Growth factors can stimulate the expansion, survival, and differentiation of cells. They are often necessary to initiate the cell cycle and promote division, and can stimulate progenitor cells to expand or produce specialized cell types. Growth factors are also critical regulators of tissue and organ construction, and play important roles in stem cell biology and during embryonic development.

Hormones are the signaling molecules produced by cells and tissues of the endocrine system, and are carried to different parts of the body primarily through the blood. Amino acid or peptide-derived hormones bind to receptors on the cell surface, but those derived from lipids can diffuse through plasma membranes. Hormones regulate a variety of processes, including metabolism, organogenesis, and immune responses.