Tumour cells can evade the immune system through various monitoring mechanisms, including negatively regulating T cell function by inhibiting the expression of immune checkpoint ligand and blocking the interaction between ligand and receptor antibodies, such as CTLA4‐Ig G, PD1‐Ig G and PD‐L1‐Ig G that have been shown to inhibit various forms of melanoma and several advanced malignancies.141. This evidence concerns the gene GAN and neoplasm.