Consistent with a reciprocal negative-feedback relationship between ECD and PERK, activated PERK negatively regulates cell growth (33, –, 35); conversely, ECD positively regulates cell growth (41) and is overexpressed in human breast and pancreatic cancer specimens, correlating with poor prognostic markers and shorter survival times (69, 70). This evidence concerns the gene ECD and familial pancreatic carcinoma.