CX3CL1 and Alzheimer disease: In addition to immune markers and their association with neurodegeneration and cognition, other molecules like brain‐derived neurotrophic factor (BDNF), genetic markers such as the triggering receptor expressed on myeloid cells 2 (TREM2) gene, immunoglobulin G (IgG) index genes, α1‐antichymotrypsin (α1‐ACT), monokine induced by gamma inteferon (MIG), tumor necrosis factor–related apoptosis‐inducing ligand (TRAIL), Fas‐associated death domain (FADD), C‐C motif chemokine ligand 25 (CCL25), CCL26, and fractalkine (CX3CL1) have also been associated with an increased risk of AD.11