CTLA4 and breast cancer: Although most studies evaluating such combination strategies have been in other tumour types such as melanoma and NSCLC[130-132], these are still relevant in breast cancers as epigenetic modifications resulting in upregulation of multiple immune checkpoints such as PD-L1, CTLA-4, TIM-3, and LAG-3 have been observed, and correlated with poorer patient prognosis in a study of breast cancer patients[133].