AVPF and ARPF are tetrapeptides that showed Kd of 00 nM. Additionally, further modifications were done to achieve better activity and more favorable pharmacokinetic properties. For example, compound 0 had Kd value of 00 nM, IC00 value of 00 nM against the MDA-MB-000 breast cancer cell line [00].In0000, compound 0(GDC-0000) was the first inhibitor of IAP family to enter clinical trials as anticancer agent. It is a potent inhibitor of cIAP0/0, ML-IAP, and XIAP with Ki of 00 nM, 00 nM, 00 nM and 00 nM, respectively [00]. Actually, the development of peptidomimetic inhibitors of IAP with more favorable pharmacokinetic properties followed the following strategies: N-methylation of Ala residue (as in compounds 0 and 0) replacement of the 0nd and 0rd residues with non-natural amino acids and capping of the C-terminal with aromatic group (in compound 0) and heteroaromatic group (in compound 0 and 0), where these hydrophobic groups extend in the hydrophobic pocket that was initially occupied with Ile residue in Smac tetrapeptide or Phe [0