FAS and tongue squamous cell carcinoma: These death receptors (DR3, DR5, Fas) initiate proteolytic cascades that activate executioner caspases (-3, -8, -9), mechanistically linking TRAIL- and Fas-mediated apoptosis pathways (Lin et al., 2015).Furthermore, Ke et al. validated the pro-apoptotic effects of PPS in tongue squamous cell carcinoma, demonstrating ROS-dependent activation of the caspase-8/caspase-3 axis as the principal mechanism.