Strauss L, Bergmann C, Szczepanski MJ, Lang S, Kirkwood JM, Whiteside TL. Expression of ICOS on human melanoma-infiltrating CD4+CD25highFoxp3+ T regulatory cells: implications and impact on tumor-mediated immune suppression. J Immunol. 2008 Mar 01;180(5):2967–80. doi: 10.4049/jimmunol.180.5.2967. PMID: 18292519.