“…Therefore, repetitive elements are hypomethylated and specific tumor suppressor genes are repressed due to hypermethylation. These may contribute to chromosomal instability and abnormal gene silencing that could promote tumor-initializing steps [2,9,14,28,38]. Promoter hypermethylation of tumor suppressor genes and DNA repair genes has been observed in a wide variety of tumors, such as colorectal, breast cancer, glioma and medulloblastoma [19,22,36].…”