PRL and cancer: In addition, the KEGG pathway of differential CFRGs was found to be enriched in “Kaposi sarcoma-associated herpesvirus infection”, “Toxoplasmosis”, “Lipid and atherosclerosis”, “FoxO signaling pathway”, “Hepatitis B”, “PD-L1 expression and PD-1 checkpoint pathway in cancer”, “NOD-like receptor signaling pathway”, “Inflammatory bowel disease”, “Prolactin signaling pathway” and “Epithelial cell signaling in Helicobacter pylori infection” (Fig. 1D).