The function of Ensembl gene identifier ENSG00000138075 (ABCG5, ATP binding cassette subfamily G member 5) is as follows. ABCG5 and ABCG8 form an obligate heterodimer that mediates Mg(2+)- and ATP-dependent sterol transport across the cell membrane (PubMed:27144356). Plays an essential role in the selective transport of dietary plant sterols and cholesterol in and out of the enterocytes and in the selective sterol excretion by the liver into bile (PubMed:11099417, PubMed:11138003, PubMed:15054092, PubMed:27144356). Required for normal sterol homeostasis (PubMed:11099417, PubMed:11138003, PubMed:15054092). The heterodimer with ABCG8 has ATPase activity (PubMed:16893193, PubMed:20210363, PubMed:27144356). {ECO:0000269|PubMed:11138003, ECO:0000269|PubMed:15054092, ECO:0000269|PubMed:16893193, ECO:0000269|PubMed:20210363, ECO:0000269|PubMed:27144356, ECO:0000303|PubMed:11590207, ECO:0000305|PubMed:11099417}.