We detected the PKM1 and PKM2 expression levels in pancreatic cancer cell lines and in patient samples (Figure 1 and Supplementary Figure S5), and found that PKM2 but not PKM1 was related to patient survival, which was in agreement with the results of other studies (Figure 1c and Supplementary Figure S5c).12 Our results are also consistent with previous studies reporting that PKM2 levels are increased in other cancer types such as HCC, pulmonary adenocarcinoma, tongue cancer and glioma.12, 26, 27, 28, 29 Older pancreatic cancer patients expressed lower levels of PKM2 (Table 1). This evidence concerns the gene PKM and central nervous system cancer.