Given the coincident Zn2+ accumulation and CDK5 activation in damaged neurons in stroke, and Zn2+ is capable of inducing tyrosine phosphorylation of multiple proteins24,40–42, it is of interest to investigate if Zn2+ may also modulate CDK5 activity through Tyr15 phosphorylation in ischemic brain injury. Here, CDK5 is linked to brain injury.