They are typically heterozygous missense substitutions, most commonly (>50% in MDS) involving p.K700E (SF3B1 NM_012433.4: c.2098A>G (p.Lys700Glu), hereafter referred to as SF3B1K700E), and have been shown to induce mis-splicing of key genes throughout erythroid differentiation [2, 3]. The gene discussed is SF3B1; the disease is myelodysplastic syndrome.