The previously realized high sensitivity of ctDNA-based MYCN copy number and ALK mutation detection in respective patients with MYCN-amplified or ALK-driven disease (6–8, 18) has provided hope that new liquid biopsy–based approaches could better capture MRD and molecular relapses in patients with TERT-rearranged neuroblastoma. The gene discussed is ALK; the disease is neuroblastoma.