definiens: means a T cell receptor comprising several subunits including ( a ) two heterologousprotein subunits including an alpha chain encoded by the TCRA gene ( HGNC ID12027 ) and a beta chain encoded by theTCRB gene ( HGNC ID 12155 ) ; ( b ) two heterologous protein subunits including a gamma chain encoded by the TCRGgene ( HGNC ID12271 ) and a delta chain encoded by the TCRD gene ( HGNC ID12252 ) ; ( c ) the pre - TCR - alpha proteinencoded by the PTCRA gene ( HGNC:21290 ) or the murine counterpart, alone or in conjunction with an alpha, beta, gamma, or delta chain as defined in ( a ) and ( b ) ; or ( d ) a single molecule, heterodimer, chimera or any engineered variantof such alpha, beta, gamma, delta, pre - TCR - alpha human or murine chain combinations