EGFR and neoplasm: In all the tumor models, the combination treatment caused profound loss in both expression and phosphorylation of EGFR and HER2, loss of phosphorylation but not expression of all other RTKs and downstream signaling proteins measured, including HER3, IGF1R, MET, SRC, AKT, MEK, ERK, loss of expression of HRAS and NRAS, and activation of caspase 3 (Fig. 6d).