MAPK3 and Alzheimer disease: Intriguingly, this kinase is known to phosphorylate ERK1/2 (Wen et al, 2004; Maréchal et al, 2007) leading to increased TAU phosphorylation and at the same time enhanced BACE1 activity (and Aβ accumulation) in another mouse model of AD (Stygelbout et al, 2014).