Using the 42 DEGs (from the hippocampus of the tame versus aggressive rats) identified here (Table 2), together with these 2393 DEGs of domestic versus wild animals (Table 8), we revealed three β-protocadherin DEGs and seven hemoglobin subunit DEGs, which are compared in Table 9 with the human homologous genes (HBB, HBD, and PCDHB9), annotated with respect to hypertension in Table S3. The gene discussed is HBB; the disease is hypertensive disorder.