This gene is well known for its role in endotoxin-mediated diarrhoea,24 is a potential colorectal cancer marker,46 and may be a link between obesity and colorectal cancer.47 Although GUCY2C expression has been detected in CD34+ progenitor cells in peripheral blood,48 a possible reflection of immune system status, the presence of GUCY2C transcripts in peripheral blood may also be a consequence of IBD disease processes. This evidence concerns the gene GUCY2C and obesity due to melanocortin 4 receptor deficiency.