2R-ohnologs in the apoptosis pathway. A network diagram of the vertebrate apoptosis pathway is shown with pairs of 2R-ohnologs (2ROs) highlighted in yellow. There are three 2RO pairs in the subnetwork: BCL2L1 and BCL2; CASP3 and CASP7; CASP8 and CASP10. Nodes are color coded: yellow signifies nodes mapping to 2ROs, while green and red signify those mapping to CIEs and COEs, respectively (see text). CASP8 and CASP10 are initiator caspases. CASP3 and CASP7 are executioner-caspases functioning downstream of these initiator caspases. IAPs are apoptosis inhibitors. The balance between antiapoptotic BCL2 and BCL2L1, and proapoptotic BAD, BAK, BAX, BID, BIM, and Puma, and Noxa determines the final activity of the intrinsic pathway of apoptosis. From [88].