KLF4 and intervertebral disk degenerative disorder: The aligned methylation data of the 71 hub genes in IDD were obtained from GSE129789, and our analysis indicated significant hypermethylation of ARHGAP27, CSNK2A1, ETV6, FNBP1L, KLF4, LTF, MGAM, MYO1F, NUCB2, RNF19B, and WWP3 (Figure 8F).