Furthermore, we were intrigued by our finding that knocking down TYK2 reduced endogenous tau levels in human cells as tau phosphorylation by tyrosine kinases is important in the pathogenesis of tauopathies, including AD17–19—an increase in tau phosphorylation on tyrosine residues correlates with the formation and accumulation of toxic tau species20,21. Here, TYK2 is linked to tauopathy.