The function of ENSG00000185803 (SLC52A2, solute carrier family 52 member 2) is as follows. Plasma membrane transporter mediating the uptake by cells of the water soluble vitamin B2/riboflavin that plays a key role in biochemical oxidation-reduction reactions of the carbohydrate, lipid, and amino acid metabolism (PubMed:20463145, PubMed:22864630, PubMed:23243084, PubMed:24253200, PubMed:27702554). Humans are unable to synthesize vitamin B2/riboflavin and must obtain it via intestinal absorption (PubMed:20463145). May also act as a receptor for 4- hydroxybutyrate (Probable). {ECO:0000269|PubMed:20463145, ECO:0000269|PubMed:22864630, ECO:0000269|PubMed:23243084, ECO:0000269|PubMed:24253200, ECO:0000269|PubMed:27702554, ECO:0000303|PubMed:20463145, ECO:0000305|PubMed:17197387}. (Microbial infection) In case of infection by retroviruses, acts as a cell receptor to retroviral envelopes similar to the porcine endogenous retrovirus (PERV-A). {ECO:0000269|PubMed:12740431, ECO:0000269|PubMed:19307586}.