– Favors the reduction of estrogens and androgens. Converts estrone (E1) to a more potent estrogen, 17beta-estradiol (E2). Also has 20-alpha-HSD activity. Uses preferentially NADH. HSD17B1 Protein, Human, Recombinant (His & Myc) is expressed in E. coli expression system with N-10xHis and C-Myc tag. The predicted molecular weight is 42.3 kDa and the accession number is P14061.