PIK3CA and serous adenocarcinoma: The 105 genes differentially expressed in the endometrial epithelia of obese mice were significantly enriched for the differential genes of both the PIK3CA/ARID1A mutant mice and BRG1 mutant mice, without a significant enrichment for the differential genes of PIK3CA/TP53 mutant mice (Fig. 4F), suggesting more similarity to endometrioid carcinoma and benign disease than to serous carcinoma.