A multisubunit protein complex involved in the signaling phase of the apoptotic process. In mammals it is typically composed of seven Apaf-1 subunits bound to cytochrome c and caspase-9. A similar complex to promote apoptosis is formed from homologous gene products in other eukaryotic organisms. [ http://www.ncbi.nlm.nih.gov/pubmed/12176339 http://www.ncbi.nlm.nih.gov/pubmed/15189137 http://www.ncbi.nlm.nih.gov/pubmed/10428850 http://www.ncbi.nlm.nih.gov/pubmed/11406413 ]