CDKN2B and glioblastoma: Additionally, TERT promoter mutations have been shown to be spatially heterogeneous/sub-clonal in some tumors (follicular thyroid carcinoma, follicular thyroid tumors of uncertain malignant potential and meningiomas) and several genes (MLH1, MGMT, CDKN2B) could exhibit spatially heterogeneous/sub-clonal methylation patterns in different tumors (glioblastoma, breast carcinoma) [52–58].