We found that the PLK1 expression negatively correlated with the HLA activity in 12 cancer types (LUAD, LUSC, TGCT, GBM, ACC, UCEC, DLBC, STAD, KICH, ESCA, SKCM, and UCS), while in 3 cancer types (THCA, KIRC, and LGG), we observed an opposite trend (Spearman correlation, FDR<0.1) (Figure 2(a)). The gene discussed is PLK1; the disease is cancer.