Flumatinib (HH-GV-678) can predominantly inhibit the autophosphorylation of Bcr-Abl in K562 cell. In higher concentration, Flumatinib can inhibit the phosphorylation of c-Kit in Mo7e cell and the phosphorylation of PDGFR in Swiss3T3 cell, however, Flumatinib has no or little effect on other tyrosine kinase including EGFR, KDR, c-Src and HER2 [1]. Flumatinib (HHGV678) effectively overcame the drug resistance of certain KIT mutants with activation loop mutations (i.e., D820G, N822K, Y823D, and A829P) [2].