We further explored the correlation between the expression of LIPT1 and eight immune checkpoints (PD-L1, CTLA4, HAVCR2, LAG3, PDCD1, PDCD1LG2, SIGLEC15, and TIGIT), and found that LIPT1 levels were correlated with the expressions of these immune checkpoints, especially PD-L1, in most cancer types (Figure 6B). This evidence concerns the gene PDCD1 and cancer.