Here, we have shown that the gene expression of CHID1 was downregulated in the brain of AD patients compared to NDHC subjects, and both in NDHC and in AD patients, the expression levels were strongly correlated with NRGN and CALB1. Only in AD patients, the CHID1 expression levels were positively correlated with IBA1 levels. Here, CALB1 is linked to Alzheimer disease.