MAP3K5 and breast carcinoma: In particular, CIB1 has been shown to function as a Ca2+‐sensitive negative regulator of ASK1 (apoptosis signal‐regulating kinase‐1)‐mediated signalling events, involved in cell survival (Yoon et al, 2009), and CIB1 depletion in breast cancer cell lines results in significant cell death (Black et al, 2015).