[Research progress on the biological functions and tumor immunotherapy of soluble T-cell immunoglobulin and mucin domain 3 (sTIM3)].

T-cell immunoglobulin and mucin domain 3 (TIM3) is an immune checkpoint protein expressed on various types of immune cells in two forms, namely membrane TIM3 (mTIM3) and soluble TIM3 (sTIM3). mTIM3 and sTIM3 share the same ligands, but less is known about functions and mechanisms of sTIM3 compared to those of mTlM3. Abnormal levels of plasma sTIM3 have been observed in patients with many diseases including cancer. Current research mainly focuses on the potential of sTIM3 as a biomarker for the diagnosis and treatment of cancer. However, there are limited investigations on sTIM3 as a target for immunotherapy. This paper provides a literature review on the recent research progress of the production and biological functions of sTIM3 and its clinical significance in cancer immunotherapy.