A) Kaplan-Meier survival curves of Apcfl/fl ;Ptenfl/fl ;Arid1afl/fl (n = 16), Apcfl/fl ;Ptenf/lfl ; Arid1afl/+ (n=28) and Apcfl/fl;Ptenfl/fl littermate controls (n = 18) following ovarian bursal injection of AdCre. Cox proportional hazards models showed that Arid1a+/+ mice died earlier than Arid1a-/- mice, with estimated hazard ratio (HR) of 2.40 for tumors with retained Arid1a expression (95% CI=1.19 - 4.83). Arid1a-/- mice died earlier than Arid1a+/- mice (HR=2.35, 95%CI = 1.19 - 4.61), and Arid1a+/+ mice died significantly earlier than Arid1a-/+ mice (HR=5.64, 95% CI = 2.82 - 11.26, p=9.6×10-7). Paired comparisons by Wald tests. B) Tumor volumes in the same groups of mice. Tumors with knockout of one or both Arid1a alleles were 1.8 and 1.6 fold larger on average than Arid1a+/+ tumors, respectively (p= 7×10-5 and .0044, ANOVA model with 3 means on log-transformed data).