CTLA4 and neoplasm: Note that the tumor digestion procedure in particular when enzymatic digestion is performed (45) but also the antibody clones and fluorochromes used [our unpublished observations and (26, 29, 46–48)] as well as the staining procedure (extra- or intracellular staining of CTLA-4) and the settings used for in vitro functional testing might all influence the analyses.