Mutations of SF3B1 of the U2 snRNP complex and U2AF35 cause aberrant 3′ splice site usage in leukemia, melanoma, breast and lung cancers (Przychodzen et al., 2013; Brooks et al., 2014; Darman et al., 2015; Alsafadi et al., 2016; Kesarwani et al., 2017). The gene discussed is SF3B1; the disease is melanoma.