This protein fragment is found in the urine of patients who suffer from debilitation and wasting from cancer, particularly cancers of the lung, breast, ovary and pancreas. It is believed to cause the wasting by degrading muscle proteins and inhibiting the creation of new proteins. Also called "cachexia-causing compound".
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.