In addition to their capacity to evoke an immune response through antigen presentation, CT antigens have been demonstrated to contribute to diverse neoplastic behaviors. CT antigens depicted here (in green) serve as key examples of how aberrant expression of these proteins can influence tumor cell regulatory networks. Abbreviations: MHC, major histocompatibility complex; TCR, T cell receptor; Ub, ubiquitin; RA, retinoic acid; PcG, polycomb group; TGFβ, transforming growth factor beta.