MYCN and neuroblastoma: Further analysis of the relationship between MDA5 immunostaining and other clinicopathological characteristics of NB, we found that in addition to histological grade of differentiation, positive MDA5 staining also strongly correlated with younger age at diagnosis (P = 0.044, χ2 test), early clinical stages (P = 0.001, χ2 test), favorable histology (P = 0.007, χ2 test), and MYCN non-amplified (P = 0.001, χ2 test) (Table 1).