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 plus 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 flow cytometry 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. We have recently submitted a manuscript describing correlative studies for NCI-C0120.