MAPK8 and Alzheimer disease: Exendin-4 acted decreasing the inhibitory phosphorylation of Ser312IRS1, Ser636IRS1, and of JNK, while restoring activating Tyr465IRS1 phosphorylation, then counteracting insulin signaling impairment, memory deficits and diminishing amyloid plaque load in APP/PS1 transgenic AD mice (Bomfim et al., 2012).