MARK2 and neurodegenerative disease: As perturbation of the PAR1b kinase activity has been shown to be critically involved in the pathogenesis of human diseases, including cancers [13,19,20] and neurodegenerative diseases [7], elucidation of a hitherto-unidentified mechanisms underlying kinase activation of PAR1b may benefit the development of innovative therapeutics against these intractable human disorders.