CD8A and neoplasm: Hence, in pancreatobiliary tumors, the adenosine rich stromal environment generated by elevated CD39 and CD73 enables neoplastic cells to escape CD8+ T-cell and NK cell immune surveillance (Ohta et al., 2006) and may facilitate cell invasion and metastatic dissemination by transiently increasing tumor vascularity (Ohta et al., 2006; Sun et al., 2010; Chiu et al., 2017; Kjaergaard et al., 2018).