For instance, in the dataset GSE29676, the AD sample group with a downregulated expression level of protein ECH1 compared to normal also have downregulated HOXB7 and upregulated ERBB2 (Pearson correlation r = 0.99 for ECH1 and HOXB7; r = −0.95 for ECH1 and ERBB2; and r = −0.94 for ERBB2 and HOXB7). Here, HOXB7 is linked to Alzheimer disease.