TNF and Cerebral ischemia: Furthermore, let-7a gene knockdown has been demonstrated to protect against cerebral ischemia/reperfusion injury by inducing reduction of apoptosis and inflammatory reaction markers, as suggested by decreased number of p-p38 MAPK- and p-JNK-immunoreactive cells and by reduced levels of TNF-α and IL-6 after let-7a inhibitor treatment 35.