C4.4A/LYPD3: ProductsC4.4A, also known as LYPD3, is a 65-100 kDa GPI-linked glycoprotein with structural similarity to uPAR. Soluble forms are generated by proteolytic cleavage or released in membrane vesicles. C4.4A is expressed in the suprabasal layers of stratified squamous epithelium, and it is upregulated at the invasive front of melanomas and carcinomas. Metastases derived from these tumors also express high levels of C4.4A. The interaction of C4.4A with Laminin-1 and -5 on neighboring cells promotes the adhesion, spreading, and migration of tumor cells.