Importantly, we note that although much of our data were obtained using FAD models and cells from FAD patients containing mutations in presenilins, alterations in γ‐secretase activity and increased levels of C99 have been detected in sporadic AD patients as well (Fukumoto et al, 2002; Yang et al, 2003; Li et al, 2004; Pera et al, 2013). This evidence concerns the gene APP and Alzheimer disease.