Further own findings by RT–PCR analysis showing an upregulation of tumour suppressor genes like fgfr2 or a downregulation of oncogenes like gadd45b, ccnb1, cflar or cdc25b in pancreatic cancer cells upon 4-PB treatment (data not shown) argue also for the involvement of general transcription regulating mechanisms like chromatin modifications, as these genes have been previously described to be deregulated in PDAC (Grutzmann et al, 2004). Here, GADD45B is linked to neoplasm.