Alves PM, et al. - In this retrospective and cross-sectional multicenter study, researchers examined the profile of tumor-infiltrating lymphocytes (TIL) in osteosarcomas of the jaws (OSJ). For this investigation, 21 OSJ samples were analyzed, and immunohistochemistry was used to assess the recognition of TIL such as CD4⁺, CD8⁺, granzyme B⁺ (GrB), programmed cell death protein⁺ (PD-1), and cytotoxic T lymphocyte-associated antigen 4⁺ (CTLA-4) in intratumoral and peripheral (stromal) regions. The Mann-Whitney test determined the association of the TIL density with the clinicopathological data. Investigators suggested that there was no link between immune infiltrate and clinicopathological findings. According to the data, OSJ exhibited a microenvironment with low TIL, including failure of efficacy of the antitumor immune response (absence of GrB+ cells), and few cells showed immunotherapeutic targets, such as CTLA-4 and PD-1.