SLCO1B1 and Hyperbilirubinemia: In addition, other gene variants – including heme oxygenase (HO)-1, hepatic solute carrier organic anion transporter 1B1 (SLCO1B1), and UDP-glucuronosyltransferase 1A1 (UGT1A1)—have been reported as risk factors of neonatal hyperbilirubinemia [6–9].