The function of SPPL2A (signal peptide peptidase like 2A, ENSG00000138600) is as follows. Intramembrane-cleaving aspartic protease (I-CLiP) that cleaves type II membrane signal peptides in the hydrophobic plane of the membrane. Functions in FASLG, ITM2B and TNF processing (PubMed:16829951, PubMed:16829952, PubMed:17557115, PubMed:17965014). Catalyzes the intramembrane cleavage of the anchored fragment of shed TNF (TNF), which promotes the release of the intracellular domain (ICD) for signaling to the nucleus (PubMed:16829952). Also responsible for the intramembrane cleavage of Fas antigen ligand FASLG, which promotes the release of the intracellular FasL domain (FasL ICD) (PubMed:17557115). Essential for degradation of the invariant chain CD74 that plays a central role in the function of antigen-presenting cells in the immune system (By similarity). Plays a role in the regulation of innate and adaptive immunity (PubMed:16829952). Catalyzes the intramembrane cleavage of the simian foamy virus envelope glycoprotein gp130 independently of prior ectodomain shedding by furin or furin-like proprotein convertase (PC)-mediated cleavage proteolysis (PubMed:23132852). {ECO:0000250|UniProtKB:Q9JJF9, ECO:0000269|PubMed:16829951, ECO:0000269|PubMed:16829952, ECO:0000269|PubMed:17557115, ECO:0000269|PubMed:17965014, ECO:0000269|PubMed:23132852}.