– C-Kit/SCF R is a type 3 transmembrane receptor for MGF (mast cell growth factor, also known as stem cell factor). c-Kit contains 5 Ig-like C2-type (immunoglobulin-like) domains and 1 protein kinase domain. It belongs to the protein kinase superfamily and CSF-1/PDGF receptor subfamily. SCF R expression on mast cells enables them to infiltrate SCF-secreting tumors where they promote tumor growth and induce local immune suppression. SCF R is up-regulated on dendritic cells by Th2-orTh17-biasing stimuli, and it is required for subsequent dendritic cell induction of Th2 and Th17 responses. SCF R protects vascular smooth muscle cells from apoptosis and assists in the recovery of cardiac function following myocardial infarction.