CDK5 and nasopharyngeal carcinoma: For example, in the genetic mouse model of NPC, increased activation of CDK5 and its activator, p25, coincides spatially and temporally with tau pathology, and CDK5 inhibition by roscovitine and olomoucine prevents cytoskeletal protein phosphorylation (Bu et al., 2002; Zhang et al., 2004, 2008).