- The PI3K-AKT (protein kinase B) and RAF/MEK (methyl ethyl ketone)/ERK (extracellular-signal regulated kinase) pathways are two of the most frequently activated signaling pathways in cancer, including colorectal cancer (CRC). KRAS (Kirsten Rat Sarcoma Viral Oncogene Homolog) mutations are detected in approximately 40% of patients with CRC and predict for resistance to EGFR (epidermal growth factor receptor) inhibitors. AKT is upregulated in approximately 60% of CRC.