Description: This 49-H4 monoclonal antibody reacts with mouse Ly-6D, which is also known as ThB. This member of the Ly6 family of GPI-anchored cell surface glycoproteins is expressed on thymocytes and splenic B cells. Moreover, common lymphoid progenitor cells that express Ly-6D have been shown to commit to the B cell lineage. Expression of Ly-6D has also been associated with Rag-1 expression along with a reduced ability to differentiate into T or NK cells. Finally, reports indicate that the level of Ly-6D expression varies in different mouse strains.