Unknown cell-surface antigen on cancer cells

The term 'Unknown cell-surface antigen on cancer cells' is a non-specific placeholder used in oncology research to describe a target protein that has not yet been molecularly identified. This typically occurs during phenotypic drug discovery, where a therapeutic agent, such as a monoclonal antibody, demonstrates anti-tumor activity, but its exact binding partner remains uncharacterized [1, 6]. While these antigens represent potential sites for targeted therapies like antibody-drug conjugates (ADCs) or CAR-T cells, the absence of a defined molecular identity prevents a full understanding of the biological mechanism and potential safety profile [2, 5]. Drugs targeting these uncharacterized antigens are often developed as 'orphan' antibodies, where the therapeutic effect is observed without prior knowledge of the target [3, 4]. Once the antigen is identified through proteomic or genomic methods, it is transitioned to a specific canonical name. Consequently, this entry does not refer to a single biological entity but rather to the state of a target prior to its formal identification.

Other names

Undisclosed cancer antigenUncharacterized tumor-associated antigenPhenotypic screening target

Not applicable