PRL and cancer: In addition to the aforementioned KEGG pathways, our results revealed other cancer-related pathways such as ‘Proteoglycans in cancer’, ‘MAPK signaling pathway’, ‘MicroRNAs in cancer’, ‘FoxO signaling pathway’, Relaxin signaling pathway’, HIF-1 signaling pathway’, ‘IL-17 signaling pathway’, ‘TNF signaling pathway’, ‘Apoptosis’, ‘Prolactin signaling pathway’,, ‘PD-L1 expression and PD-1 checkpoint pathway’ and so on (Table S4).