TAP2 and Alzheimer disease: In contrast, we did not observe increased levels of mRNA for the immunoproteasomal subunit PSMB8 (MS cingulate = 1.782 ± 0.599; control cingulate = 1.182 ± 0.226; AD temporal cortex = 1.617 ± 0.320; control temporal cortex = 0.511 ± 0.167; Supplemental Figure 12) or the antigen peptide transporter TAP2 (MS cingulate = 0.458 ± 0.203; control cingulate = 0.993 ± 0.333; AD temporal cortex = 0.357 ± 0.054; control temporal cortex = 0.453 ± 0.098; data not shown) in either MS or AD brain tissue.