NFS1 and cancer: However, in addition they induce many factors that can result in MDR, including the activation of autophagy9 (caused by excessive ROS, which then prevents cancer cell apoptosis by degrading the ROS) and up-regulating the levels of cysteine desulfurase10 (NFS1 protein, which can catalyse cysteine to produce endogenous hydrogen sulfide and consume ROS, which prevents cancer cell apoptosis).