HIF1A and rectal cancer: OA also exerted anticancer effects on rectal cancer cell lines through several molecular mechanisms; it stimulated the reactive oxygen species (ROS) and NADPH oxidase 2 (NOX2) and inhibited the overexpression of HIF-1α in a dose-dependent manner, leading to G1/S cell arrest and, subsequently, to the inhibition of rectal cancer cells proliferation [125].