Meanwhile, a Pearson correlation coefficient was used for estimating the association between SELL and other checkpoint molecules (CD274, CTLA4, HAVCR2, LAG3, PDCD1) and Teff (effector T-cell) gene signatures (CD8A, CXCL6, CXCL10, EOMES, GZMA, GZMB, IFNG and TBX21) which have been reported as biomarkers related with cancer immunotherapy (Socinski et al., 2018). Here, PDCD1 is linked to cancer.