CSN3 and breast neoplasm: Because Ca2+ is an ubiquitous intracellular messenger relevant for cell survival, apoptosis and proliferation (Azimi et al., 2014; Monteith et al., 2007), it was proposed that breast tumour KCa channels promote pro‐oncogenic functions at least in part by Ca2+‐dependent signalling pathways (Kunzelmann, 2005; Ouadid‐Ahidouch and Ahidouch, 2013).