Using 6 separate data sets from 6 different cancer cell lines (including 1 OCCC), only 1 cell line (cholangiocarcinoma, HuCCT1) showed a statistically significant increase in PIK3R3 in ARID1A-deficient cells (Supplemental Figure 8), suggesting that the molecular mechanisms that lead to PIK3R3 upregulation in bladder cancer cells may be uncommon in other tumor types. Here, PIK3R3 is linked to urinary bladder cancer.