To study the immediate and long-term effects of TrkA/NTRK1-signaling upon exposure to IR, TrkA/NTRK1-negative human neuroblastoma cell lines, SY5Y and Kelly, were engineered to conditionally express TrkA/NTRK1 upon addition of tetracycline (TET) and designated SY5Y-TRA and Kelly-TRA, respectively. This evidence concerns the gene NTRK1 and neuroblastoma.