PBM with NIR light exposure augments NO bioavailability via multiple mechanisms. First, PBM rests on its ability to photo-dissociate NO from cytochrome c oxidase (CcO) in mitochondria. Second, PBM increases NO bioavailability from intracellular stores, especially engaging heme proteins, including CcO, hemoglobin (Hb), or myoglobin. The schematics show hemoglobin composed of a heme prosthetic group, two α-globin, and two β-globin chains. Third, PBM has been shown to increase NO production from NOS via increasing the expression level and phosphorylation.