Since previous studies have shown that the level of CD8+ TIL directly correlates with the expression of several APM components in different tumours50–52, we decided to investigate the expression level of several APM components (HLA class I, B2M, TAP1, TAP2, TAPBP, constitutive proteasome: PSMB5, PSMB6, PSMB7, and immunoproteasome: PSMB8, PSMB9, PSMB10) in the OS tumours using RNA-seq data. This evidence concerns the gene PSMB9 and neoplasm.