To tackle KRAS G12C inhibitor resistance, we evaluated the effectiveness of combining AMG510 (sotorasib, KRAS G12C inhibitor) with buparlisib (PI3K inhibitor), linsitinib (IGF1R inhibitor), gefitinib (EGFR inhibitor), trametinib (MEK inhibitor), or SHP099 (SHP2 inhibitor) in multiple KRAS G12C–mutant cancer cell lines, including both sensitive ones (H358, H1373, and MIAPACA2) and resistant ones (H2030 and SW1573). This evidence concerns the gene IGF1R and cancer.