ENTPD1 and neoplasm: Overall, we show that the TME of NSCLC upregulates CD39 expression in multiple cell types including NK cells (CD56+), B cells (CD19+) and fibroblasts (CD90+ cells) suggesting a shared trigger such as TGF-β and hypoxia potentiating CD39 expression.11 While CD39 is mainly expressed in stromal areas, CD73 is found in both tumor nest and stroma.