NOX4 and acute kidney injury: Shikonin, a naphthoquinone from Lithospermum erythrorhizon roots, reduces oxidative stress by inhibiting NOX2 and NOX4 enzymes activities and expression in doxorubicin-induced cardiotoxicity (Kazumura et al., 2016), and sepsis-induced acute kidney injury (Peng et al., 2022) animal models respectively.