MYCN and neuroblastoma: Many studies have shown that MYCN is an independent factor for unfavorable prognosis.[11, 12] The key action of MYCN in inducing NB has been confirmed in vivo and in vitro.[13, 14] The number of MYCN copies required to be defined as amplification is still controversial.[15] For our patient, 2.6% of MYCN copies demonstrated triploid amplification at diagnosis, and no copies were examined upon recurrence.