CDKN1A and medulloblastoma: The aim of this study was to determine the prevalence of genetic polymorphisms (codon 31 and 3’UTR) and protein expression of the cyclin-dependent kinase inhibitor 1A (CDKN1A) gene, and to determine the risk of developing CNS-like medulloblastoma (16 cases), astrocytoma (15 cases) and ependymoma (10 cases).