While HSD17B3 doesn’t seem to be crucial for basal testosterone production in mice (Rebourcet et al., 2020), HSD17B3 deficiency in humans causes abnormal masculinization, infertility, and very high rates of gender dysphoria, which confirms its role in the development of major sexual characteristics (Longo et al., 1975). Here, HSD17B3 is linked to Infertility.