An active flavonoid component oroxin A, which is obtained from the traditional Chinese herb Oroxylum indicum (L.)Kurz, increased ER-Tracker Red-positive cell population and upregulated ER stress-related proteins activating transcription factor 4 (ATF4) and binding immunoglobulin protein (GRP78), caused cell cycle arrest at the G2/M phase and induced senescence in human breast cancer cells while p38-specific inhibitor SB203580 blocked ER stress induced senescence [79]. This evidence concerns the gene ATF4 and breast cancer.