RBBP4 and neuroblastoma: The RBBP4 immunostaining was noted in 30/42 (71.4%) NB tissues, and higher in specimens with poor differentiation (P = 0.011, Pearson chi-square test), higher MKI (P = 0.016, Pearson chi-square test), or advanced INSS stages (P < 0.001, Pearson chi-square test, Supplementary Table 6).