ENTPD1 and neoplasm: The inhibitory receptors PD-1 and CTLA-4 displayed elevated expression on the CD39+ subset (Figures 3B and 3C), supporting the previous scRNA-seq data, which identified higher expression of genes associated with exhaustion on tumor-infiltrating CD39+ MAIT cells, such as CTLA4 or HAVCR2 (Figure 1D).