Other significant risk factors included symptoms such as pain, hypertension, and tachycardia at diagnosis, increased LDH and ferritin levels, poorly differentiated histology, primary tumor localization in the pelvis or retroperitoneum, MIBG-positive tumors, N-MYC gene amplification, and structural chromosomal alterations (SCA) in tumor tissue (Table 4). This evidence concerns the gene MYCN and neoplasm.