HIF1A and liver cancer: In vitro, carnosine has been shown to decrease HIF-1α protein levels in cardiac myoblasts (1 μM, well within the physiological range) [167], human colon cancer cells (50 and 100 mM) [219], human liver cancer cells (100 μM of a membrane-permeable derivative) [220], and in vivo in retinal ischemia in mice (1000 mg/kg, single treatment) [221].