PICALM and Alzheimer disease: AD genome-wide association studies suggest a crucial role of several proteins involved in membrane trafficking such as PICALM, SORL1, BIN1.14 In addition, several endolysosomal proteins such as EEA1, Rab3, Rab7, LAMP1 and LAMP2 were found increased in the CSF of AD patients.15 These data suggest that endosomal dysmorphologies could be associated with amyloid pathology in AD and could thus be detected in blood cells from AD patients at an early stage of the disease.