ATF1 and cancer: At FDR 0.05, we identified six differential fusion-cancer pairs (Fig. 3d, Supplementary Data 7), five of which were more frequent in AYAs, including WT1-EWSR1 (9.2% vs. 0.4%) and EWSR1-ATF1 (2.9% vs. 0.6%) in soft tissue sarcoma, EML4-ALK (16.4% vs. 1.5%) in non-small cell lung cancer, RET-NCOA4 (8.2% vs. 0%) in THCA, and DNAJB1-PRKACA (16.3% vs. 0%) in hepatobiliary cancer.