ABSTRACT BACKGROUND Neuroblastoma (NB) is one of the most common extracranial solid tumors occurring in infancy and childhood with highly variable outcomes. Polycomb group (PcG) proteins are epigenetic gene silencers. Enhancer of zeste homolog 2 (EZH2) is a member of the polycomb repressor complex 2 (PRC2) group, with the main function to catalyze the polycomb repressor compl…