FASLG and cancer: Specifically, PD was shown to trigger the apoptosis of cancer cells via multiple mechanisms, such as Fas/FasL upregulation, mitochondrial impairment, ROS regeneration, Bcl-2 family modulation, apoptosis-inhibitor suppression, and activation of apoptosis-related pathways, such as mitogen-activated protein kinase and the inhibition of pro-survival pathways, including PI3K signaling (5).