TP53 and neuroblastoma: Using a pair of neuroblastoma cell lines derived from the same patient, before and after cytotoxic therapy, we previously demonstrated that the cell line derived after therapy, at disease relapse, had mutant non-functional p53, and was more resistant to chemotherapy compared to the cell line derived at diagnosis before therapy, which had wt functional p53 (Tweddle et al., 2001a).