HMOX1 and ischemia: As shown by our immunohistochemistry (IHC) co-localization of endogenous enzymes for bilirubin synthesis in neurons, we suggest that in WT mice, ischemia induced elevation in the level of endogenous heme from neurons and/or RBC extravasation from the infarct as well as in the activity of HO in a TRPM2-dependent manner in the infarct area.79