These findings are in accordance with the overexpression of Nrf2 and HO-1 detected in the cartilage of patients and animals with osteoarthritis [51,52], suggesting that the high expression of the antioxidant/detoxificant proteins detected in the hippocampus of mice with knee osteoarthritis might act as an endogenous protective response against the oxidative stress generated by this pathology. This evidence concerns the gene HMOX1 and osteoarthritis.