CSNK2A1 and intervertebral disk degenerative disorder: The methylation analysis of the hub genes showed that 11 genes (ARHGAP27, CSNK2A1, ETV6, FNBP1L, KLF4, LTF, MGAM, MYO1F, NUCB2, RNF19B, and WWP3) were hypermethylated in IDD.