To further investigate the association between PSMB9 and tumor immunity, we performed Pearson correlation analyses to assess the relationship between PSMB9 and a total of 150 immune pathway regulatory genes across various tumor types using data from the UCSC Xena database and found that PSMB9 was closely correlated with five categories of immune pathway regulatory genes—including chemokines, receptors, MHC molecules, immunoinhibitors, and immunostimulators—in nearly all tumor types (Figure 4B). Here, HLA-C is linked to neoplasm.