TAP2 and Alzheimer disease: As LMP and TAP genes are encoded in one block in the LMP2-TAP1-LMP7-TAP2 order in the HLA class II region [22], we examined whether the LMP2-TAP1-LMP7-TAP2 haplotypes marked by SNPs tested here might reveal stronger associations with AD risk, age at diagnosis or severity than each SNP individually.