In fact, pembrolizumab+Tmab showed clinical benefit in patients with advanced Tmab-resistant, HER2+/PD-L1+ breast cancer.29 As for GC patients, phase 2 clinical trials of combination therapy of pembrolizumab with Tmab, capecitabine and oxaliplatin for HER2+ metastatic esophagogastric adenocarcinoma are ongoing and have reported an improved anti-tumour effect (NCT02954536). This evidence concerns the gene ERBB2 and breast cancer.