The p53-independent pathway mainly consists of Fas/APO1 part of the tumor necrosis factor receptor family (5). The Fas/APO1 receptor contains an extracellular cysteine-rich domain and an intracellular death domain (5). When the Fas/APO1 receptor binds its FasL ligand, trimerization of the receptor occurs and the death domain recruits FADD (5). FADD has a death receptor domain that recruits caspase 8 to its death-inducing signaling complex resulting in the activation of a caspase cascade (5). p53 increases the number of Fas/APO1 receptors but apoptosis through this receptor remains independent of p53 (5). The IGF-RP3 gene blocks prosurvival signals by binding to IGF-1 (5). p53 is known to target IGF-RP3 to induce apoptosis, however, apoptosis by IGF-RP3 can still occur in the absence of p53 (5). Any sort of mutational inactivation or reduction in p53 can result in apoptosis inhibition and carcinogenesis.