There are a number of cancer-regulated mechanisms that can prevent PCD such as increased expression of anti-apoptotic Bcl-2 proteins to prevent mitochondrial outer membrane permeabilization, expression of caspase inhibitors such as X-linked inhibitor of apoptosis protein (XIAP) or cytokine response modifier A (CrmA), mutations in proteins such as p53, ATM, Rb, or PTEN, and dysregulation of NFκB, Myc, Ras, or Akt, among many others [37,38]. Here, XIAP is linked to cancer.