PDCD1LG2 and head and neck cancer: Analysis of the CLS cohorts of colorectal, head and neck, and breast cancers identifies a significant increase in PDL1 expression via immunohistochemistry (q = 1.03 × 10−9), as well as increases in HAVCR2 (q = 0.0077), LAG3 (q = 7 × 10−4), and PDL2 (q = 0.0357) RNA expression in colorectal cancer in elderly patients (Figure 2B) and a significant increase in LAG3 expression (q = 0.0112) in patients with HPV-negative head and neck cancer (Figure 2C), while no significant changes in immune checkpoint gene expression were identified in the breast cancer cohort (Figure 2D).