GARP, also known as leucine rich repeat containing 32, is a type I membrane protein with twenty-two leucine-rich repeats and a short intracytoplasmic region. GARP was identified based on the analysis of gene expression profiling of Treg and Th cells following TCR stimulation. Since GARP is expressed in CD4+, CD25+, FoxP3+ cells (Tregs), it may be a candidate for cell surface marker for Treg cells.