This gene encodes a receptor tyrosine kinase. This gene was initially identified as a homolog of the feline sarcoma viral oncogene v-kit and is often referred to as proto-oncogene c-Kit. The canonical form of this glycosylated transmembrane protein has an N-terminal extracellular region with five immunoglobulin-like domains; a transmembrane region; and an intracellular tyrosine kinase domain at the C-terminus. Upon activation by its cytokine ligand; stem cell factor (SCF); this protein phosphorylates multiple intracellular proteins that play a role in in the proliferation; differentiation; migration and apoptosis of many cell types and thereby plays an important role in hematopoiesis; stem cell maintenance; gametogenesis; melanogenesis; and in mast cell development; migration and function. This protein can be a membrane-bound or soluble protein. Mutations in this gene are associated with gastrointestinal stromal tumors; mast cell disease; acute myelogenous leukemia; and piebaldism. Multiple transcript variants encoding different isoforms have been found for this gene.