For gastrointestinal inflammation, Bamias and colleagues [32] validated reference gene stability in IBD patients and healthy individuals, and they concluded that using suboptimal reference genes such Gapdh, Actb and β2m to quantify mRNA expression such as for TNF-α in inflamed and non-inflamed colon and ileum altered the results from significant to non-significant. The gene discussed is B2M; the disease is inflammatory bowel disease.