PBX1 and pancreatitis: We examined 5 sections each from 3 mice that developed adenocarcinoma and observed that GFAP, PBX1 and CELSR3 expression was co-localised with GFP in tumor associated PaSC's (Figure S3A, S3B, S3C respectively), and although PBX1 (but not CELSR3) was detected in the stroma in pancreatitis, it did not co-localise with GFAP, suggesting that it was not expressed in activated stellate cells.