IgA - IgE receptor - IGF type 1 receptor - IGF type 2 receptor - IgG - IgM - immediate-early protein - immune cell - immune system - immunoglobulin - immunoglobulin joining region - immunoglobulin variable region - immunologic receptor - immunology - In vivo - infrared spectroscopy - inhibin - inhibitor - inhibitory gi G-protein - Inorganic chemistry - insect protein - Insulin - insulin receptor - insulin-like growth factor I - Integral membrane protein - intein - intercellular adhesion molecule-1 - interferon receptor - interferon type I - interferon type II - interferon-alpha - interferon-beta - interleukin receptor - interleukin-1 receptor - interleukin-2 receptor - interleukin-3 - interleukin-3 receptor - intermediate filament - intermediate filament protein - intermembrane space - Intermolecular force - International Union of Pure and Applied Chemistry (IUPAC) - interphase - intracisternal A-particle gene - Intramolecular force - intron - Inverse agonist - invertebrate peptide receptor - invertebrate photoreceptor - Ion channel - ion channel gating - Ionic bond - ionization potential - iron–sulfur protein - isoenzyme - isoleucine - Isomer - Isothermal titration calorimeter - Isotopic tracer