PDCD1 and diffuse large B-cell lymphoma: The results of correlation analysis based on bulk RNA sequencing data of DLBCL showed that HAVCR2 was positively correlated with CD8A (r = 0.46, p < 0.001), CD8B (r = 0.28, p < 0.001), LAG3 (r = 0.56, p < 0.001), PDCD1 (r = 0.33, p < 0.001), CTLA4 (r = 0.44, p < 0.001) and TIGIT (r = 0.35, p < 0.001) (Fig. 3f).