Post operatively, suppression of several immune functions occurs, and may last for weeks. The cellular immunity undergoes suppression, while the humoral immunity remains almost entirely intact (1). These changes in cell mediated immunity may impact systemic resistance to infection as well as metastatic processes. Specifically, NK cells have a pivotal role in defense from neoplastic processes. Studies have shown that high levels of activity of NK cells are associated with long term survival (1). Therefore, understanding of the processes which cause post-operative immune suppression, and prevention of such suppression, are of clinical significance.