Moreover, methylation (5mC) in cell-free DNA (cfDNA) have been widely observed in human diseases, regions with consistently altered 5mC levels for FNDC3B in circulating cfDNA during progression from low-grade glioma to glioblastoma could be used as markers for development of minimally invasive screening of early diagnosis and surveillance (36, 37). The gene discussed is FNDC3B; the disease is central nervous system cancer.