These data demonstrate that SF3B1 mutation enhances the sensitivity of tumor cells to the spliceosome modulator E7107 and SAA but not pladienolide B. SF3B1 mutation therefore sensitizes cells to pharmacologic targeting of wild-type SF3B1, consistent with the observation that the growth of SF3B1-mutant endometrial cancer and uveal melanoma cell lines was impaired by deletion of wild-type, but not mutant, SF3B1 [84]. The gene discussed is SF3B1; the disease is endometrial cancer.