The CD117 mast/stem cell growth factor receptor tyrosine kinase (KIT) is critical for haematopoiesis, melanogenesis, and stem cell maintenance. KIT is commonly activated by mutation in cancers including acute myeloid leukaemia, melanoma, and gastrointestinal stromal tumours (GISTs). The kinase and the juxtamembrane domains of KIT are mutation hotspots; with the kinase domain mutation D816V common in leukaemia, and the juxtamembrane domain mutation V560G common in GISTs. Given the importance of mutant KIT signalling in cancer, we have conducted a proteomic and phosphoproteomic analysis of D816V- and V560G-KIT mutations, using an FDCP1 isogenic cell line model.