Identification of a novel mechanism of immunosuppression in tumour cell lines

How do cancers manage to escape the attention of the immune system? We know that they are somehow able to mask their presence, but how? The aim is to investigate a novel molecule, soluble CTLA-4 (sCTLA-4) in cancer cell lines. An important feature of this molecule is that it can suppress immune responses, so it now becomes important to determine if cancer cells are using sCTLA-4 to switch off anti-tumour immunity. We will examine various cancer cell lines for the presence of sCTLA-4 by confocal microscopy. Which types of cancer produce it and what happens when we remove it?