PARP2 and osteosarcoma: • The median immune infiltrate level in high-grade osteosarcoma with poor-risk and adverse survival outcome was lower than other cancer types, with concomitant low T-cell receptor clonalities.• High immune infiltrate represents an enrichment of tumor-intrinsic immunosuppressive pathways• Low immune infiltrate showed a high number of deleted genes and negatively correlated with PARP2 expression levels