CDK12 and breast cancer: For example, CDK12 positivity was correlated with HER2 positivity (Naidoo et al., 2018); and MIEN1 overexpression facilitates migration, invasion and metastasis in breast cancer (Zhao et al., 2017) and it is negatively correlated with disease free survival (Kushwaha et al., 2019) mainly in HER2-positive subtypes.