PDCD4 and adenocarcinoma: Studies indicate thatCOX2/PGE2-mediated repression of PDCD4 occurs via the induction of miR-21(Peacock et al., 2014).Consistent with this, PDCD4 protein levels decrease progressively during CRCtumorigenesis, as normal tissue transforms to adenocarcinoma (Ma et al., 2013a; Mudduluru et al., 2007) and loss of PDCD4 protein issignificantly associated with reduced patient survival (Mudduluru et al., 2007).