The 30-H12 monoclonal antibody specifically binds to Mouse CD90.2, an alloantigen known as Thy-1.2, expressed on thymocytes, mature T cells, epithelial cells, neurons, hematopoietic stem cells, and fibroblasts. CD90 is a membrane glycoprotein that regulates the adhesion and signal transduction in T lymphocytes, and the adhesion of thymocytes to thymic stroma.

The interaction between 30-H12 and the antibody to the CD3/TCR complex upregulates thymocytes signal transduction and apoptosis and downregulates mature T cell proliferation. The 30-H12 antibody seems to be unable to cross-link with CD90.1.