PHF1 and Alzheimer disease: We also observed anaccumulation of AD associated tau, another autophagy substrate, and its phosphorylatedform (using PHF1 antibody) by immunofluorescence in structures resemblingtau tangles (a hallmarkof AD) in cells expressing DsRed-tau 4R when autophagy was inhibited by Baf A1 or when CALM was knocked down (Fig. 2d).