In addition, Mao et al. reported that Procyanidins can play an anti-lung cancer activity by inhibiting inflammation and inducing tumor cell apoptosis, and the mechanism of action is related to the inhibition of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) eicosan-like pathway and the initiation of caspase-3 apoptosis pathway, suggesting that Procyanidins can be used as a potential preventive and therapeutic drug against lung cancer, which has been also supported by a recent clinical study (Mao et al., 2016; Mao et al., 2019). The gene discussed is PTGS2; the disease is lung cancer.