MAPT and tauopathy: In several tauopathies including PSP, increased activity of extracellular-regulated kinase 1 & 2 (ERK-1 /ERK-2), increased expression of stress activated protein kinase (SAPK/ JNK) and calcium/ calmodulin-dependent kinase II (CaM Kinase II) overexpression occurs [77], affirming the role of tau phosphorylation.