HMOX1 and Alzheimer disease: In many papers, to achieve a marked increase in HO-1 level were necessary high concentrations of Aβ, in the range 10—20 μM, whereas in our study a significant HO-1 over-expression was detected as low as 25 nM sAβ and 6.25 nM fAβ, these concentrations being close to those detected in AD brain which are well below 1 μM (Nag et al., 2011 and references therein).