KRAS and colorectal carcinoma: Genetic anomalies of the phosphatidylinositol-3 kinase (PI3K) pathway, such as PI3K amplification/mutation, AKT mutation, or PTEN loss, result in activation of this pathway, leading to tumorigenesis and have been implicated in the resistance of KRAS mutant CRC cells to MEK inhibition (Temraz et al., 2015).