ERBB2 gene mutation mainly happens in ERBB2high cancers, such as cervical squamous cell carcinoma, stomach adenocarcinoma, breast invasive ductal carcinoma, uterine corpus endometrioid carcinoma, cholangiocarcinoma, and bladder urothelial carcinoma (Figure 2A). This evidence concerns the gene ERBB2 and endometrial endometrioid adenocarcinoma.