AD-associated single nucleotide polymorphisms (SNPs) in the MS4A cluster fall within a linkage disequilibrium (LD) block encompassing MS4A2, MS4A3, MS4A4A, MS4A4E, MS4A6A and MS4A6E, with strong evidence for an AD association at the MS4A6A locus [8]. The gene discussed is MS4A3; the disease is Alzheimer disease.