Indeed, a phase I trial of regorafenib plus nivolumab in gastric cancer and CRC demonstrated longer overall survival for patients treated with combination therapies in comparison with patients treated with nivolumab or regorafenib mono-therapy, although patients were not stratified according to potential response or toxicity markers, including PDL-1 levels, TMB, and molecular characterization (i.e., micro-satellite instability (MSI) or MMR, HER2, or RAS mutation status) [50]. This evidence concerns the gene ERBB2 and gastric cancer.