ThemouseAnti-FR4antibody,cloneTH6,bindstofolatereceptor4(FR4),acellsurfacereceptorforfolicacid(vitaminB9).FR4isconstitutivelyexpressedathighlevelsonmouseCD4
+CD25
+naturalregulatoryT(Treg)cells.Thehighexpressionofthis
MarkerincombinationwithCD4andCD25allowsthedistinctionbetweenTregcellsandothertypesofTcells.