Target of the antiproliferative 1 (TAPA1), also known as CD81, is found in the plasma membrane in lymphocytes and plays an important role in the regulation of lymphoma cell growth. This transmembrane 4 superfamily (TM4SF) protein is primarily found on CD4+CD8+ thymocytes as well as broadly in the periphery, with high-level expressed in cell cohorts such as B-cells, NK cells, macrophages, and dendritic cells.
