APP and fibrosis: For instance, PSEN1 is required for the cleavage and activation of NOTCH, which is characteristic of rodent and human fibrosis.[8, 9] This together with our previous discovery of decreased APP and Aβ in human and rodent cirrhotic liver[10] led us to the hypothesis that reduced APP and BACE1 may shift the γ‐secretase activity toward NOTCH cleavage thereby contributing to the loss of Aβ in fibrotic liver.