HER3 was highly expressed in skin cutaneous melanoma, prostate adenocarcinoma, intestinal-stomach adenocarcinoma and estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), HER2− breast cancer (ER+/PR+/HER2−), while generally lower in normal tissues (Fig 1A). Here, ERBB3 is linked to prostate adenocarcinoma.