More recently, Zheng's work demonstrated that ectopic expression of FoxO3a enhanced p21CIP1/WAF1 expression and berberine, a compound derived from traditional Chinese medicine-induced apoptosis in human lung adenocarcinoma cells [41], indicating the important role of FoxO3a in the initiation of apoptosis in cancer cells. This evidence concerns the gene CDKN1A and lung adenocarcinoma.