TRAV1-2 and neoplasm: This high frequency has been linked to a biased usage of TRAV12–2 variable gene of the TCRα-chain, as well as to the lack of expression of the complete MART-1 transcript in the thymus, causing a lack of central tolerance against T cells recognizing this epitope from a normal protein.40 MART-1 has been studied as a model tumor antigen in melanoma for several decades.