v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog; This is the receptor for stem cell factor (mast cell growth factor). It has a tyrosine-protein kinase activity. Binding of the ligands leads to the autophosphorylation of KIT and its association with substrates such as phosphatidylinositol 3-kinase (Pi3K) (976 aa)