To investigate the mechanism of the protective effect of CST3 on hyperbilirubinemia, we measured the solubility of UCB, and found that CST3 could increase the solubility of UCB in a cell-free system (Figure 2a), but it did not have significant difference compared with CTL (CST3 solvent, PBS). This evidence concerns the gene CST3 and Hyperbilirubinemia.