One of the major problems in immune therapy is that we do not understand why some treatments work and others fail in patients. We use samples from patients treated with anti-CTLA4 plius locoregional therapy to better understand how immune based approaches work in HCC. We are studying tumor samples from patients on our studies using gene expression analysis and perform flowcytometry studies on PBMC. These studies are ongoing. So far we have been able to demonstrate that patients with tumor infiltrating T cells are more likely to respond to anti-CTLA4 plus locoregional therapy.