Absence of mutations in KRAS and NRAS does not imply the sensitivity to the therapy, but their presence can exactly predict the lack of response.combining mTORand EGFR inhibition as well as simultaneous inhibition of mTORand Bcl-2/Bcl-xL may improve therapeutic outcome in patients withKRAS- or BRAF-mutant CRC [143, 144]. Here, NRAS is linked to colorectal carcinoma.