CLDN7 and breast cancer: CAMKK1 has been reported to be involved in apoptosis in MCF7 cells [42], CCND3 is linked to HER2 status in breast tumours [43], CLDN7 expression levels have been correlated with the metastatic potential of breast carcinomas [44], 53BP1 has been proposed as a breast cancer biomarker [45] and WNT5B gene expression is regulated by β-estradiol in MCF7 cells [46] and the WNT family play an important role in several human cancers [47–49].