CD274 and neoplasm: Additionally, high expression of myeloid‐derived suppressor cells (MDSCs) in OS can remodel the tumor microenvironment (TME) to promote tumor progression, while PI3Kδ/γ is highly expressed in MDSCs, and application of PI3Kδ/γ inhibitors induces CD8+ T‐cell infiltration and upregulation of PD‐L1 levels in OS cells.159, 160