As physiological HER3 expression was reported in normal tissue, similarly, abnormal expression of HER3 has often been linked to a variety of different cancers, including breast cancer, colorectal carcinoma, squamous cell carcinoma of the head and neck, uveal melanoma, and gastric, ovarian, prostate, and bladder cancers, as shown in Table 1 [36,37,38,39]. This evidence concerns the gene ERBB3 and urinary bladder cancer.