In particular, trastuzumab has greatly improved the therapeutic approach of advanced BTC but has little evidence in other digestive cancers, as proved by Nicola et al. Trastuzumab in combination with cytotoxic therapies in HER2-positive BTC has increased the tumor response rate from 35% to 47%, improving progression-free survival from 5.5 months to 6.7 months and overall survival from 11.1 months to 13.8 months. This evidence concerns the gene ERBB2 and neoplasm.