Interestingly, the fraction of M2 macrophages in Group 4 medulloblastoma were positively correlated with the risk score and were significantly correlated with the expression level of four signature genes (CCNY, SYNE3, CYB5D2, and SELENOV) and four hub genes (GLI2, PAX6, RUNX2, and ZIC1). Here, CYB5D2 is linked to medulloblastoma.