To investigate the mechanism by which DDX1 induces mTORC1 pathway activation, we performed immunoprecipitation of DDX1 followed by mass spectrometry–based proteomics in two MYCN-amplified neuroblastoma cell lines with and without DDX1 coamplification to identify proteins that associate with DDX1 in the context of high DDX1 expression, respectively (Fig. 4A–C). The gene discussed is MYCN; the disease is neuroblastoma.