The results showed that, compared with the paired adjacent normal tissues, there were 47 different metabolites in PDAC tissues with high RIOK3 expression (n=17) (Figure 2A), and pathway enrichment analysis suggested that these differential metabolites were associated with arginine synthesis and arginine and proline metabolism (Figure 2B), whereas only 28 differential metabolites were found in cancer tissues with low RIOK3 expression (n=10) (Supplementary Figure 1A), and the pathway enrichment analysis did not reveal any pathway associated with arginine metabolism (Supplementary Figure 1B). Here, RIOK3 is linked to cancer.