KRAS and colorectal carcinoma: Indeed, pharmacological inhibition of GSK3, which is also negatively regulated by RAS/PI3K/AKT, partly depends on MYC to induce apoptosis in KRAS-driven human cell lines.163 Conversely, in KRAS mutant NSCLC and CRC cell lines, chemotherapy-induced cytotoxicity appears to be dependent on MYC inhibition.31 These studies imply context-dependent feedback between both oncogenes in regulating apoptosis induction.