KRAS and neoplasm: There is conflicting data on the role of TP53 mutation as a predictive biomarker for anti-EGFR based therapy: in two studies with chemorefractory RAS-unselected or KRAS/BRAF wild-type mCRC patients treated with cetuximab based chemotherapy, TP53 mutation appeared to predict cetuximab sensitivity, particularly in patients with KRAS/BRAF wild-type tumours [16, 17].