MYCN and neuroblastoma: Wallick et al. showed that α‐difluoromethyl‐ornithine (DFMO) and S‐adenosylmethionine decarboxylase inhibitor (SAM486) treatments induce significant accumulation of the p27kip1 protein and cause p27kip1/Rb‐coupled G1 cell cycle arrest in MYCN‐amplified neuroblastoma tumour cells 20.