PTGS2 and gastric cancer: Han et al. found that lycopene inhibits cell proliferation and induces cell apoptosis by reducing the levels of ROS, and thereby inhibiting ROS-activated EGFR/Ras/ERK and p38 MAPK signaling pathways and suppressing NF-κB p50/p50-mediated COX-2 gene expression in the Caucasian GC cell lines AGS [23].