Our findings were reinforced both in an independent sulforhodamine B (SRB) assay of cell proliferation, and also in a larger cell panel that included four primary neuroblastoma cell lines with MYCN gene amplification, three cell lines with diploid MYCN and four engineered SHEP cell lines expressing mutated or wild-type exogenous MYCN protein (Table S2). Here, MYCN is linked to neuroblastoma.