GO terms of black_M6 module showed that several genes involved in complement activation (Mbl1, Crp, Cd46, Cft, Masp1, C1r, etc.), IL-6 production (Cd24, Aqp4, Sirpa Adora2b, Gas6, Nod2, and Myd88, etc.), classical Wnt signaling pathway (Fgfr2, Gpc3, Notch1, Fzd6, and Hdac2, etc.), autophagy (Map1lc3B, Vcp, Nod2, Atg12, Vps13d, and Rab12, etc.), and acute inflammatory response (C4pbpa, Ptger3, Cd46, Masp1, and Serping1, etc.)were immediately increased after PVL and remained high up to day 14 post-PVL. Here, HDAC2 is linked to periventricular leukomalacia.