HIF1A and Alzheimer disease: However, the decrease in HIF‐1α levels in AD mouse brains at 24 h post Ab‐TP‐MDNPs treatment was insignificant, probably due to the transient change and short half‐life of HIF‐1α that requires an optimal time after the Ab‐TP‐MDNPs treatment for detecting a significant change,[7, 34, 35, 36, 37, 38] while in this study samples were collected at 24 h post last injection to provide sufficient time for Ab‐TP‐MDNPs to be cleared.