NCIt definition : A protein antigen that is comprised of the monosaccharide N-acetylgalactosamine (GalNAc)
bound to serine or threonine by O-linked glycosylation. Aberrant expression of Tn
antigen by all blood cell lineages is associated with a rare hematological disorder
called Tn-syndrome. Increased expression of this monosaccharide modification is also
associated with some cancers and this antigen is being investigated for use as either
a biomarker or therapeutic target for these associated malignancies.;