KRAS and colorectal carcinoma: In a recent study, amplification of the human epidermal growth factor receptor 2 (HER2) gene was shown to promote cetuximab resistance in a KRAS/NRAS/BRAF/PI3KCA wild-type PDX model with metastatic CRC and was found to predict responses to antiepidermal growth factor receptor (EGFR) and anti-HER2 antibodies (Gupta et al., 2024).