The function of ENSG00000057252 (SOAT1, sterol O-acyltransferase 1) is as follows. Catalyzes the formation of fatty acid-cholesterol esters, which are less soluble in membranes than cholesterol (PubMed:16154994, PubMed:16647063, PubMed:32433613, PubMed:32433614, PubMed:32944968, PubMed:9020103). Plays a role in lipoprotein assembly and dietary cholesterol absorption (PubMed:16154994, PubMed:9020103). Preferentially utilizes oleoyl-CoA ((9Z)-octadecenoyl-CoA) as a substrate: shows a higher activity towards an acyl-CoA substrate with a double bond at the delta-9 position (9Z) than towards saturated acyl- CoA or an unsaturated acyl-CoA with a double bond at the delta-7 (7Z) or delta-11 (11Z) positions (PubMed:11294643, PubMed:32433614). {ECO:0000269|PubMed:11294643, ECO:0000269|PubMed:16154994, ECO:0000269|PubMed:16647063, ECO:0000269|PubMed:32433613, ECO:0000269|PubMed:32433614, ECO:0000269|PubMed:32944968, ECO:0000269|PubMed:9020103}.