PDCD4 and neoplasm: In addition, Nagao et al. [26] demonstrated that miR-21 downregulated its molecular targets programmed cell death 4 (PDCD4) and tissue inhibitor of metalloproteinase (TIMP3) in PDAC, potentially explaining the tumor-invasive behavior of PDAC and poor survival of patients with high miR-21 levels Altogether, these data suggest that high miR-21 expression is related to poor outcome of both gemcitabine and 5FU-based therapy.