As the cancers progress, studies have shown that the upregulation of PD-L1 was due to the activation of the Janus kinase 2/signal transducers and activators of the transcription 1 (JAK2/STAT1) signalling pathway in EC and other cancers such as colorectal, pancreatic, and gastric cancer [47,48,49,50]. The gene discussed is STAT1; the disease is gastric cancer.