The prototype example of this is imatinib, a drug originally developed for the breakpoint cluster region/Abelson murine leukemia viral oncogene homolog 1 (BCR-ABL)—driven chronic myeloid leukemia, being found to be active against mast/stem cell growth factor receptor (KIT) driven gastrointestinal stromal tumors (GIST) [17]. This evidence concerns the gene KIT and gastrointestinal stromal tumor.