Immunohistochemical staining revealed that MZF1-uPEP was expressed in nuclei and cytoplasm of tumor cells (Figure 6A and Figure S12A), and detected in 22/42 (52.4%) NB cases, with lower expression in those with elder age (P=0.038), poor differentiation (P=0.024), higher mitosis karyorrhexis index (MKI, P=0.037), or advanced INSS stages (P=0.007, Table S7). The gene discussed is MZF1; the disease is neuroblastoma.