A methyl thiazol tetrazolium (MTT) assay showed that an anti-IL-20 mAb (7E) suppressed IL-20-mediated cell proliferation in these three pancreatic cancer cell lines (Supplementary Fig. 2c–e), suggesting that IL-20 is pivotal in pancreatic cancer cell proliferation. Here, IL20 is linked to familial pancreatic carcinoma.