TFAP2A and breast cancer: MiR-876-5p has been validate as a tumor suppressor in multiple tumors including breast cancer, gastric cancer, colorectal cancer, head and neck squamous cell carcinoma, liver cancer and so on [16, 17, 34–36], and its downstream targets includes TFAP2A, MITF, RASAL2, vimentin, DNMT3A and so on [16, 17, 34–36].