MAPT and Alzheimer disease: Subjects with variant p21cip1 also had significantly greater p-tau and NFT accumulation in the occipital lobe than subjects with common p21cip1: with p-tau results reaching statistical significance in subjects with mild and advanced AD only (p = 0.014 and p = 0.029 respectively) and NFT results reaching significance irrespective of the severity of disease (p = 0.023) (Fig. 5).