ENTPD1 and non-small cell lung carcinoma: The beneficial effects of targeting CAFs, in experimental models, rely on the presence of an adaptive immune response6,40 and increase the effectiveness of checkpoint inhibitors indicating CAFs suppress T cell responses and facilitate suppression via PD-1 in vivo.33 In vitro studies show CAFs can limit T cell proliferation,41 alter patterns of cytokine production,42–44 promote apoptosis3 and upregulate co-inhibitory receptor expression.44 We have extended these findings to show human NSCLC-derived CAFs also induced expression of CD39 on activated T cells via TGF-β.