CTLA4 and hepatocellular carcinoma: For the first time, based on analysis, we found that PLOD2 expression was positively correlated with 12 immune checkpoint genes (BTN2A1, BTN2A2, CD209, CD276, CD47, CD80, CD86, CTLA4, HAVCR2, SIRPA, TIGIT, VYCN1) in patients with HCC.