PRDM9 and central nervous system cancer: In glioma cells, histone methyltransferases G9a, EZH2, MLL1 and MLL2 (Chang et al., 2009; Cheung et al., 2012; Liu F. et al., 2013; Kondengaden et al., 2016; Wiese et al., 2016; Banasavadi-Siddegowda et al., 2018) regulated the methylation level of lysine located in histone (Table 3); these modifications were closely related to gene transcription regulation and genome integration (Heddleston et al., 2012; Zhou et al., 2016).