VMA21 and acute kidney injury: Similar to the above examples, circ-VMA21 was reduced in patients with septic AKI and also in the LPS-stimulated HK-2 cells; upregulation of circ-VMA21 in a rat CLP model alleviated oxidation stress, cellular apoptosis, inflammation, and tissue injury in septic AKI, purportedly by functioning as a sponge of miR-9-3p [44].