Fig 2.

Schematic representing intrinsic and extrinsic apoptosis initiation. When activated, p53 activates Bax and Bak, then Suma and Nova, leading to Apaf1 cleavage of pro-caspase 9 into active caspase 9. Bcl-2, along with Bcl_XL and MCL1, can downregulate the activation of cytochrome C, halting proapoptotic signals from the intrinsic pathway. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and potentially other activation methods of extrinsic apoptosis remain active in synovial sarcoma.