JNK signalling mediating apoptotic cell death has been well-documented [53, 54], thus activation of JNK signalling by DKK3 may result in the induction of apoptosis in breast cancer, in line with the findings by other groups [55], although other non-canonical WNT signalling pathways may also be involved like TGF-β signalling [56]. Here, TGFB1 is linked to breast cancer.