Neu5Gc are found in animal tissues, fungi, yeast, and bacteria,...

Neu5Gc are found in animal tissues, fungi, yeast, and bacteria, but are not expressed at significant levels on healthy human tissues, as humans cannot synthesise Neu5Gc due to an inactivating mutation in the CMAH gene. However, elevated Neu5Gc has been observed in tumours, including breast, ovarian, prostate, colon, and lung^[1]and pancreatic^[2]and endometrial cancers. The presence of Neu5Gc is prognostically important, and correlates with invasiveness, metastasis and tumour grade. As a result, Neu5Gc has been proposed as a tumor antigen, and its detection in human serum and other bodily fluids could be utilised as a diagnostic and prognostic marker in a range of human cancers.