CSNK1A1 and Alzheimer disease: These findings support the hypothesis that CK1δ has a possible role in the modulation of tau, which is further supported by the findings that CK1 is an active physiological kinase in neuronal cells and that the expression of CK1δ is strongly increased in AD brains probably leading to severe and pathological disruption of tau-MT binding (Ghoshal et al., 1999; Yasojima et al., 2000; Hanger et al., 2007).