To examine whether the synergy between FGFR and VEGFR inhibitors found in GIST T-1R cells was solely due to the inhibition of the aforementioned signaling pathways, we also utilized lapatinib, a well-known potent EGFR and ErbB2 inhibitor, and crizotinib (c-MET and ALK inhibitor) and used them in combination with BGJ398 or regorafenib. Here, ERBB2 is linked to gastrointestinal stromal tumor.