PPARG and glaucoma: It was proved that NAM could provide neuroprotective effects under stress through preventing metabolic disruption, increasing mitochondrial size and motility, which was reported in studies of glaucoma in rodents.[31, 54] Additionally, as a cofactor or co‐substrate for many enzymes and NAD+ supplementation by NR or NMN can promote injured mitochondria clearance via mitophage,[55] facilitate DNA repair[24a] and regulate lipid metabolism via PPARγ signaling as well,[28b] which could illustrate potential mechanism of NAM protective effective from NIHL.