ERBB2 and neoplasm: The ratio between the IC50 of the RTKi with and without MRTX849 is presented in Fig. 2D. These drug studies demonstrated that the sensitization of 4NQO-L tumor cells to MRTX849 by HER inhibitors (lapatinib, afatinib, and erlotinib) was superior to that of MET or AXL inhibitors, and thus further support the findings that EGFR and HER2 play a role in limiting the efficacy of KRASG12Ci.