Certain tumor types, including renal cell carcinoma, pancreatic neuroendocrine tumors, and hepatocellular carcinoma, have been shown to enhance systemic CRP levels indirectly, through tumor-derived production of pro-inflammatory cytokines such as interleukin-6 (IL-6), which in turn stimulates hepatic CRP synthesis [28]. This evidence concerns the gene IL6 and pancreatic neuroendocrine tumor.