PDCD4 and pancreatic intraductal papillary-mucinous neoplasm: In Bon-1 pancreatic neuroendocrine cells [23], ovarian cancer cells [36] and intraductal papillary mucinous neoplasm samples [37], PDCD4 acted opposite to our finding in regulating p21Waf1/Cip1, and in NB4 human acute promyelocytic cells, PDCD4 had no significant effect on p21Waf1/Cip1 expression [38].