Figure 4 illustrates several CPAs, their cellular compartmentalization, and enrichment in diverse biological pathways. Certain markers, like cancer antigen 125 (CA-125) and carcinoembryonic antigen cellular adhesion molecule-5 (CEACAM-5), already serve as serum tumor markers for pancreatic and ovarian cancers (282, 283); however, their limited specificity and sensitivity hinder their reliability for accurate diagnoses (155). Notably, Melanoma-associated antigen 3 (MAGE-A3), a CTPA, has proven to be an attractive target in undifferentiated sarcoma (284). This evidence concerns the gene MAGEA3 and undifferentiated (embryonal) sarcoma.