MAPT and Alzheimer disease: However, the discovery modules may also interact with several AD risk genes, including (Major Histocompatibility Complex, Class II, DR Beta 1/5) HLA-DRB1/HLA-DRB5, Bridging Integrator 1 (BIN1), PICALM (endocytosis and signaling), ABCA7 and MAPT (ion transport), APP (signal transduction), or CLU (exocytosis) [24].