No significant changes were detected in neutrophil (CD45high Ly6G+), B cell (CD45high CD19+ B220+), monocyte (CD45high CD11b+ F4/80+ FSClow) or macrophage (CD45high CD11b+ F4/80+ FSChigh) numbers between normal brains or brains harboring Myc/p53DD medulloblastomas. This evidence concerns the gene PTPRC and medulloblastoma.