Inhibition of γ‐secretase activity, but not β‐secretase activity, causes synaptic and memory deficits in a mouse model of AD which is associated with accumulation of APP‐CTF (Tamayev et al, 2012), suggesting that APP‐CTFs, next to Aβ peptides, are also toxic species causing neurodegeneration. The gene discussed is APP; the disease is Alzheimer disease.