There are elements of immune over stimulation resulting in a cascade of cytokine activation following surgery. These cytokines include tumour necrosis factor alpha (TNF-a) and interleukin 1B (IL-1B). These can stimulate the production and release of other cytokines including interleukin 6 (IL-6). IL-6 results in the production of C-reactive protein (CRP) and other acute phase proteins through the hepatic component of this response.