Furthermore, in contrast to ellipticine and the TOP1 inhibitor camptothecin, which induced p53 expression as expected, 5 μmol/L MYCMI-7 had no effect on p53 expression early (3 hours) and only a minor increase late (24 hours) after treatment in HCT116 cells and in MYCN-amplified Kelly neuroblastoma cells (Fig. 5E; Supplementary Fig. S4E). This evidence concerns the gene TOP1 and neuroblastoma.