Each human neoplasm has its own molecular bases for tumor development and biology that are generally described as the tissue‐specific characteristics of the tumor. There is no doubt that neuroblastoma (NBL) is not the same as Wilms tumor, and Wilms tumor is not the same as retinoblastoma, though they may have a common mechanism to initiate and sustain abnormal growth. One of the reasons for these variations is the difference inherent in progenitor cells, from which the tumor is derived and whose developmental lineage is specifically determined. Neuroblastoma, one of the most common pediatric solid tumors, originates from the neural crest anlage of the sympathicoadrenal system. For a long time, pediatric oncologists have sought answers to the questions of why NBL can have such diverse clinical behavior as aggressive, unremitting growth on the one hand, and differentiation or spontaneous regression on the other, and why these patterns are affected by the patient's age. Recent research has focused on nerve growth factor (NGF), the first growth factor discovered 45 years ago. It provides a key to opening the door to understanding some aspects of the neuroblastoma mystery. It does so by linking NBL and normal developmental pathways of the sympathicoadrenal system. Med. Pediatr. Oncol. 31:113–115, 1998. © 1998 Wiley‐Liss, Inc.