The inclusion of hypocretin sequences would improve the correlation (R2 = 0.985, N = 16) but inclusion of erythropoietin would suppress the correlation (R2 = 0.953, N = 15), suggesting that HCRT could be a relatively more important candidate as a blocker or promoter when compared to EPO for targeting in drug development with application to Alzheimer's disease clinical trials. Here, HCRT is linked to Alzheimer disease.