CD8A and neoplasm: In a study by Shi et al., the PI3Kδ/γ inhibitor (S)-(-)-N-[2-(3-hydroxy-1H-indol-3-yl)-methyl]-acetamide (SNA) enhanced the efficacy of anti-PD-1 antibodies in the treatment of osteosarcoma, and further studies showed that SNA inhibited MDSCs thereby enhancing the anti-tumor effects of CD8+ T cells (105).