Can reduce the dialdehyde protein-binding form of aflatoxin B1 (AFB1) to the non-binding AFB1 dialcohol. May be involved in protection of liver against the toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen. Homodimer. Expressed in colon, kidney, liver, pancreas, adenocarcinoma and endometrium. Belongs to the aldo/keto reductase family. Aldo/keto reductase 2 subfamily.