MED1 and breast cancer: On the other hand, MED1 has been demonstrated to be a regulator of several miRNAs known to be involved in BC such as miR-10b-5p, -100-5p, -17-5p, 18a-5p, -191-5p, 193b-3p, 205-5p, -326, -422a and -425 suggesting its importance in BC pathogenesis.