MAPK3 and Cerebral ischemia: Studies have shown that pretreatment with U0126 and SB203580 could effectively down-regulate ERK1/2- and p38 MAPK-mediated anti-cyt c/cleaved caspase-3 apoptotic signaling, respectively, in the ischemic areas during the subacute phases after cerebral ischemia (21, 48).