A sporadic case of MDS with de novo mutation of KCNN2 has also been reported.[87]KCNN2 encodes the SK2 subunit of the small‐conductance calcium‐activated potassium (SK) channel, which mediates repolarizing/hyperpolarizing currents in some neurons in the central nervous system.[88]KCNN2 is highly expressed in the cerebellum, and some patients harboring KCNN2 variants exhibit cerebellar eye signs[86] or cerebellar ataxia.[89] Collectively, the discovery of KCNN2‐related MDS reinforces the view that the cerebellum is involved in the pathogenesis of MDS. The gene discussed is KCNN2; the disease is myelodysplastic syndrome.