These nominated clusters upregulated key marker genes of activation, dysfunction, and differentiation that have been used to identify tumor specificity [16–18], such as CXCL13, TIGIT, PDCD1 (PD1), ENTPD1 (CD39), TOX, HAVCR2 (TIM-3), and LAG3 (Fig. 4E). This evidence concerns the gene PDCD1 and neoplasm.