It has been suggested that epilepsy can be caused by BK channel gain-of-function (GOF) (Okawa et al., 2000; Du et al., 2005) and loss-of-function (LOF) mutations in the KCNMA1 gene (Stafstrom and Carmant, 2015; Li et al., 2018). The gene discussed is KCNMA1; the disease is epilepsy.