Although JAK2/STAT3 pathway activation leads to the increased expression of genes associated with cell proliferation, differentiation, and survival after cerebral ischemia, the function of activated JAK2/STAT3 is controversial; some studies have reported an association with survival,13, 30, 38, 39 while others have indicated a relationship with cell death.13 The gene discussed is JAK2; the disease is brain ischemia.