GA was found to have induced the apoptosis of A549 cells in a time and dose‐dependent manner arrested the cells at the G0/G1 phase in vitro, and downregulated the mRNA expression of cyclin‐D1 and COX‐2, suggesting that GA could inhibit the proliferation of tumor cells through apoptosis induction and cell cycle arrest.206. The gene discussed is PTGS2; the disease is neoplasm.