CP and Alzheimer disease: Indeed, the 36 genes reported as differentially expressed in AD CP epithelium by microarray, and in some cases [17] also by quantitative PCR (Bergen et al. Tables 1 and 2 in [26]), were regulated similarly in AD whole CP tissue in our study (r2 ~ 0.7), but to a lesser magnitude (by ~ 35%, as indicated by linear regression in Fig. 1d).