Previously, the UGT1A7*3 allele exhibited modestly significant association with colorectal cancer (OR = 2.39; P = 0.02) [57], lung cancer [62], endometrial cancer [63] and pancreatic cancer (OR = 1.98; P = 0.003) [64] with a particularly strong association in smokers with pancreatic carcinoma who were younger than 55 years (OR = 4.7; P = 0.0009), suggesting the magnitude of the observed associations may be modified by environmental interactions. Here, UGT1A7 is linked to endometrial cancer.