In our current study, the expression of 12 immune checkpoint genes (CD40, TNFRSF4, CD86, LAIR1, TNFRSF14, HAVCR2, CD244, TMIGD2, TNFRSF9, KIR3DL1, TNFRSF8, and CD48) were downregulated in PAAD tissues compared with the normal group. The gene discussed is CD48; the disease is pancreatic adenocarcinoma.