UGT1A1 and Hyperbilirubinemia: However, the group treated with UGT1A1 antisense in combination with CsA had a significant (p < 0.05) small increase in serum UCB within physiological ranges (physiological UC hyperbilirubinemia) compared with the CsA-treated group (1.17 ± 0.09 vs. 0.198 ± 0.12) and CsA + CH-treated group (1.17 ± 0.09 vs. 0.1825 ± 0.14) (Figure 1C).