The expression levels of Grb2 and four cytoskeletal proteins – α-tubulin, vimentin, α-smooth muscle actin (α-SMA) and stathmin1 – in human whole-brain post-mortem tissue lysates of AD patients and non-AD whole brain (control) tissue lysates were compared by western blotting (Fig. 1A). Here, GRB2 is linked to Alzheimer disease.