Ripretinib (QINLOCKTM) is a novel type II tyrosine switch control inhibitor being developed by Deciphera Pharmaceuticals for the treatment of KIT proto-oncogene receptor tyrosine kinase (KIT)-driven and/or platelet derived growth factor receptor A (PDGFRA)-driven cancers, including gastrointestinal stromal tumour (GIST). The gene discussed is KIT; the disease is cancer.