GADD45A and preeclampsia: MAPK and/or Erk/MAPK signaling is a common pathway downstream to many preeclampsia associated markers or molecules such as stress sensor Gadd45α [33] and heat shock protein 27 (Hsp27) [34], oxidative stress [35] and HB-EGF in invasion and anti-apoptosis upon hypoxia [36], sFlt-1 [37] and angiotensin [38] in maintaining endothelial function, and angiogenic regulator CCN3 [39].