While this expression of CTLA-4 on neoplastic peripheral T-cells would be in keeping with the inducible expression of CTLA-4 on activated T-cells, it calls into question the mechanisms that underlie the seeming loss of intrinsic CTLA-4-mediated control of T-cell proliferation (72, 73) as well as the activating signals which drive CTLA-4 expression in neoplasms. Here, CTLA4 is linked to neoplasm.