In another study, the combination of first‐line chemotherapy drugs such as FOLFOX and cetuximab improved OS and PFS after treatment in chemotherapy‐refractory CRC patients with KRASG13D, while no response was observed in CRC cell lines with KRASG12X/Q61X mutations or KRASWT CRC cell lines with BRAF mutations or no expression of PTEN or EGFR proteins.259, 260. This evidence concerns the gene EGFR and colorectal carcinoma.