To determine the specificity of #5333 and #5338 for MYCN, we used two different doxycycline (Dox)-inducible neuroblastoma cell systems for repression of MYCN expression: shMYCN SK-N-BE(2)-C (MYCN-amplified) and shMYCN Kelly (MYCN-amplified) cell lines. This evidence concerns the gene MYCN and neuroblastoma.