Multiple immune cell types were observed to be negatively correlated with PLK4 expression in various cancer types, such as GBM, lung adenocarcinoma (LUAD), prostate adenocarcinoma (PRAD), skin cutaneous melanoma (SKCM), etc. TCGA, CGGA_693, and CGGA_325 datasets showed negative correlations between PLK4 mRNA levels and multiple TIICs/TILs (Supplementary Figure 8). Here, PLK4 is linked to lung adenocarcinoma.