MYCN and Wilms tumor: It is proved that the expression level of MYCN increased in Wilms tumor,29, 30, 31, 32 and MYCN gene can up‐regulate the expression of CRABP‐II in Wilms tumor patients to promote tumor progression.33 A study executed by Williams et al showed that MYCN gene contributed to the development of Wilms tumor through manifold mechanisms.34 In addition, the effect of MYCN gene polymorphisms on Wilms tumor may be related to RA signaling pathway.35 The contradiction of results may be caused by the small sample size and racial differences.