XIAP and neoplasm: In breast cancer studies, thymoquinone could prevent proliferation of cancer cells by inducing p38 phosphorylation via activation of ROS generation, suppressing tumour growth in vivo, downregulating the expression of antiapoptotic genes such as, XIAP, survivin, Bcl-xL and Bcl-2, inhibiting production of Ki-67 tumour aggressor, and upregulating the level of catalase, superoxide dismutase and glutathione [119].