PIK3R3 expression was altered in cases of ovarian cancers with somatic mutations in USP4, SPTBN1, SORBS2, and TBC1D2. Collectively, our results suggest that PIK3R3 is a useful prognostic marker for ovarian cancer and can therefore be exploited for developing therapeutic strategies for this cancer type. The gene discussed is SPTBN1; the disease is ovarian cancer.