SLC10A6 encodes a sodium-dependent organic anion transporter (SOAT) that mediates cellular uptake of sulfoconjugated steroid hormones 1. The protein exhibits seven-transmembrane domain topology and functions as a glycosylated, 46 kDa plasma membrane protein 1. SOAT transports dehydroepiandrosterone sulfate, estrone-3-sulfate, and pregnenolone sulfate in a sodium-dependent manner with competitive kinetics 1. Beyond steroid sulfates, SOAT also transports sulfoconjugated bile acids and organosulfates, including taurolithocholic acid-3-sulfate and sulfoconjugated pyrenes 1. The transporter is highly expressed in testis, with significant expression in placenta and pancreas 1. Biologically, SOAT delivers sulfoconjugated steroid precursors to reproductive organs, where steroid sulfatases convert them to biologically active free steroids 2. A notable role involves transporting the estriol precursor 16α-hydroxydehydroepiandrosterone 3-sulfate at fetal blood vessel endothelium 3. In spermatogenesis, SOAT expression in germ cells suggests involvement in male fertility regulation 4. Rare loss-of-function variants in SLC10A6 impair transport activity or membrane expression, potentially affecting reproductive function 4. Experimentally, SOAT inhibitors demonstrate antiproliferative effects on hormone-dependent breast cancer cells 5, establishing therapeutic potential as a drug target.