TH and neuroblastoma: This observation was confirmed by the induction of tyrosine hydroxylase protein expression, a marker of neuronal differentiation specific for this cell line.20 The morphological changes were similar to those observed after treatment with retinoic acid, a well‐known neuroblastoma differentiating agent17 [Pozzoli G. and Cenciarelli C., personal observation], suggesting that ASA might force neuroblastoma cells to exit cell cycle and to differentiate towards the neuronal‐like phenotype.