Besides, exploratory analysis of previous trials such as FIRE-3 trial (first-line therapy with FOLFIRI44 plus either cetuximab or bevacizumab in 592 KRAS exon 2 wild-type metastatic CRC patients) and CALGB/SWOG 8040545 (a phase III trial that compared the addition of bevacizumab or cetuximab to infusional fluorouracil, leucovorin, and oxaliplatin or fluorouracil, leucovorin, and irinotecan as first-line treatment of advanced CRC), showed CMS classification is prognostic for mCRC; however, at present time has no direct impact on clinical decision-making and may need further refinement. The gene discussed is KRAS; the disease is colorectal carcinoma.