RASSF1 and ependymoma: The tumors suppressor genes RASSF1, CDKN2A, CDKN2B, p14ARF and TP73, as well as other genes potentially involved in the tumorigenesis of ependymomas, such as CASP1, MGMT, TIMP3 and THBS1 are epigenetically silenced by aberrant promoter methylation in subsets of ependymomas [110, 111].