Intracellular signaling pathways downstream of tumor necrosis factor (TNF) receptor superfamily receptors. The Fas, tumor necrosis factor receptor type 1 (TNFR1) and tumor necrosis factor receptor type 2 (TNFR2) receptors are shown extending through the cell membrane with their extracellular domains projecting into the extracellular space. Various adaptor proteins and signal transducing molecules that convey signals initiated by the binding of the ligands Fas ligand (FasL) to Fas and TNF to TNFR1 and TNFR2, respectively, are shown, as is the crosstalk between various molecules and pathways. Functional domains within a protein are shown as colored blocks. Recruitment of one protein to another is indicated by the juxtaposition of like-colored and like-shaped domain blocks. BID, beta interaction domain; cIAPs, cellular inhibitors of apoptosis; FADD, Fas-associated death domain protein; IKK, IκB kinase; JNK, c-Jun N-terminal kinase; MAP3K, mitogen-activated protein 3 kinase; NEMO, NF-κB essential modulator protein; RIP, receptor-interacting protein; T2K, TRAF2-associated kinase; TANK, TRAF family member associated NF-κB activator; TRADD, TNF receptor-associated death domain protein; TRAF, TNF receptor-associated factor.