GSTM1 and cerebrovascular disorder: In light of these observations, we would like to propose the following scenario: 1) when microhemorrhage occurs as the result of aging, traumatic brain injury or cerebrovascular disease, Aβ can act as a sealant preventing further leakage of toxic blood components; 2) Aβ peptides aggregate around the leaked Hb limiting its toxicity; 3) Aβ binds to heme preventing the generation of toxic reactive oxygen species and promoting heme degradation [55]; 4) Aβ chelates and sequesters free iron thereby greatly reducing direct iron-elicited oxidative toxicity.