In consistence with previous reports, we found that ATP6AP2 expression is significantly higher in tumor tissues than that in normal tissues (P < 0.01), moreover, level of ATP6AP2 expression in PAAD is positively correlated with the expression level of CTNNB1 (β-catenin encoding gene) and Wnt target gene AXIN2 (Fig. 4a). The gene discussed is ATP6AP2; the disease is pancreatic adenocarcinoma.