We found that the PLK1 expression levels were negatively associated with immune scores in 10 cancer types (LUSC, TGCT, STAD, GBM, ESCA, PAAD, LUAD, UCEC, ACC, and DLBC) while were positively associated with immune scores in 4 cancer types (KIRC, THCA, THYM, and LGG) (Spearman correlation, FDR<0.1) (Figure 1(a)) among the 33 cancer types analyzed. This evidence concerns the gene PLK1 and cancer.