For metastatic colorectal cancer, the latest (2022) European Society for Medical Oncology (ESMO) Clinical Practice Guideline (CPG) for diagnosis, treatment, and follow-up provides recommendations including testing for KRAS, NRAS exons 2, 3 and 4, and BRAF mutations in all patients at the time of metastatic colorectal cancer (mCRC) diagnosis (I, A) due to the limited benefit of anti-EGFR therapies in such patients [165–168]. This evidence concerns the gene NRAS and metastatic colorectal cancer.