TERF2 and Alzheimer disease: While this highlights the primary importance of TRF2 out of all the Shelterin subunits, the maintenance of the T-loop structure is also dependent on the collaborative effort with other subunits, as demonstrated by Mahady et al. The study revealed significant telomere attrition in the precuneus, the area that is involved in memory deficits in the prodromal stage of AD.