Similarly, Xu et al. reported that cytisine, a natural alkaloid, produces significant cytotoxic effects against lung cancer A549, NCI-H23, and NCI-H460 cells and in vivo (rat model) by inducing apoptosis via an increase in ROS and loss of membrane potential; increasing BAD, cleaving PARP, and cleaving caspase-3 expressions; and decreasing Bcl-2, pro-PARP, and pro-caspase-3. Here, BCL2 is linked to lung cancer.