PDCD1 and angioimmunoblastic T-cell lymphoma: Among the 4 ST-sequenced AITLs, 3 expressed high CD40-CD40LG activity, accompanied by the upregulation of immune-suppressive-associated genes, such as CCL17 and PDCD1. Conversely, the remaining patient displayed an uncommon absence of CD40-CD40LG activity but harbored a phagocytosis-associated tumor-associated macrophage (TAM)-enriched TME, which correlated with significantly reduced relapse rates and longer event-free survival (EFS), highlighting the critical value of precise TME stratification in tailoring AITL therapeutic strategies.