In the analysis of immune checkpoint (IC) genes (Figure 6A), PLAG1 exhibits a positive correlation with key IC genes such as HAVCR2 and CD274 in cancer types like LGG and PRAD, while showing a negative correlation in head and neck squamous cell carcinoma (HNSC) and STAD. This evidence concerns the gene PLAG1 and head and neck squamous cell carcinoma.