SOX11 and neuroblastoma: Neuroblastoma-associated genes such as SOX11 are amplified and cyclized by eccDNA, which is derived exclusively from the amplified alleles, whereas eccDNA contributes considerably to genome amplification, and its mediated extrachromosomal cyclization is a potential driver of high levels of focal genome amplification, which promotes high expression of SOX11 (Fig. 2C).3