The dose-dependent effects of these compounds were examined in the following NB cell lines: (1) MYCN2: NB cells with and without doxycycline-inducible MYCN overexpression; (2) SK-N-Be1: tumor cells derived from a patient at diagnosis (responsive to chemotherapy); (3) SK-N-Be2(c): tumor cells derived from the same patient after relapse (drug resistant). This evidence concerns the gene MYCN and neuroblastoma.