In support of these in vitro data, legumain deficiency in the 5xFAD transgenic mouse model of AD (Oakley et al., 2006) causes a drop of Aβ40, Aβ42 and amyloid plaque burden, while it increases spine density, and prevents deficits in LTP and learning and memory (Zhang et al., 2015). The gene discussed is LGMN; the disease is Alzheimer disease.