PRL and cytomegalovirus infection: KEGG analysis showed that the top 10 candidate gene-related pathways mainly included “primary immunodeficiency”, “prolactin signaling pathway”, “human cytomegalovirus infection”, “JAK-STAT signaling pathway”, “type B hepatitis”, “T-cell receptor signaling pathway”, “toll-like receptor signaling pathway”, and so on (Supplementary Table S5, Figure 2B).