1D0J360421942ENSG00000049249ENSMUSG00000028965Q07011P20334NM_001561NM_001077508NM_001077509NM_011612NP_001552NP_001070976NP_001070977NP_035742CD137, a member of the tumor necrosis factor (TNF) receptor family, is a type 1 transmembrane protein, expressed on surfaces of leukocytes and non-immune cells.

[5][6] Its alternative names are tumor necrosis factor receptor superfamily member 9 (TNFRSF9), 4-1BB, and induced by lymphocyte activation (ILA).

It is of interest to immunologists as a co-stimulatory immune checkpoint molecule, and as a potential target in cancer immunotherapy.

[9] Ongoing studies are researching CD137 as a biomarker for atherosclerosis as well as CD137 antagonists as potential therapeutics to reduce the symptoms associated with the condition.

The mechanism connecting CD137 bidirectional signaling to the promotion of atherosclerosis is related to CD137 mediation of epithelial cell damage.

When the CD137/CD137L complex interacts with endothelial cells, including those lining vascular structures, it induces the upregulation of molecules that promote inflammation and damage.

In chronic cases, this results in excessive inflammation of the epithelial tissue, leading to cell damage and the formation of atherosclerotic inflammatory lesions.

CD137/ligand stimulation has been found to lead to stronger anti-tumor responses due to cytotoxic T cell activation and is being examined as a possible anticancer therapy.