KCNN4 and neoplasm: Current knowledge suggests that BK (Lallet‐Daher et al., 2009; Parihar et al., 2003; Stegen et al., 2015) and SK4 (Ouadid‐Ahidouch et al., 2004; Parihar et al., 2003; Steinle et al., 2011) activities are required for malignant growth of several tumour‐derived cell lines and of xenografts in immunocompromised mice, highlighting a general role of KCa channels for cell cycle‐specific functions (Huang and Jan, 2014; Pardo and Stuhmer, 2014).