ERBB2 and breast cancer: Likewise, high expression of cyclin-dependent kinase 12 (CDK12), a cyclin-dependent kinase involved in DNA damage repair and coamplified with HER2 at chromosome 17, was found to be associated with disease recurrence and poor survival; this high CDK12 expression activates WNT1- and WNT2-mediated Wnt/β-catenin signaling cascades to enhance the stemness of HER2+ BC and, in turn, induces trastuzumab resistance [96].