ARID1A and endometrial cancer: In the multivariate analysis performed using a Cox proportional hazards model, patients with endometrial cancer with mutant PTEN and ARID1A had a better RFS than those with wild-type PTEN and ARID1A (HR = 0.42, 95% CI = 0.25–0.69, P < 0.001; HR = 0.58, 95% CI = 0.35–0.97, P = 0.040, respectively) (Supplementary Table S3).