ERBB2 and gastrointestinal stromal tumor: Increased Axl levels have been linked to resistance to Imatinib in gastrointestinal stromal tumors, Lapatinib in HER-2 positive breast tumor cells53, BMS-754087 in Rhabdomyosarcoma54, and metformin in PCa55, as well as erlotinib in non-small cell lung cancer (NSCLC)32.