Besides, the expression of eight CCGs (CRY2, DBP, NR1D1, NR1D2, PER2, PER3, RORA, and TIMELESS) was negatively regulated by methylation and positively regulated by CNV in glioma, which is consisting with previous studies that DNA methylation and CNV can promote abnormal gene expression [39–41]. The gene discussed is PER2; the disease is central nervous system cancer.