HBB and Alzheimer disease: As shown in Figure 9A (a and b), the volcano plot showed a significantly decreased level of hemoglobin α (Hbα) and β (Hbβ) in the brain tissue of AD animals compared with WT animals (Hbα: P = 0.024; Hbβ: P = 0.023), which were preserved in AD animals with PBM treatment (Hbα: P = 0.049; Hbβ: P = 0.0037).