TFs involved in CRCs co-opted by MYCN in neuroblastoma (PHOX2B, HAND2, ISL1 and GATA3)15,16 and the PAX3–FOXO1 and PAX7–FOXO1 fusion proteins in alveolar rhabdomyosarcoma (MYOD1, MYOG, SOX8 and MYCN)17,18 constituted the strongest dependencies specific to each tumour type. Here, ISL1 is linked to rhabdomyosarcoma.