Our current understanding of a/ T cell receptor (TCR) ex- pressing T cells advanced from function and specificity to the molecular organization ofthe TCR.We now know that the TCR a and chains together express specificity for (antigenic) peptides presented by the "responder" M H C allele, thus explain- ing the phenomenon of MHC restriction at a molecular level. Surprisingly even though our perception of the molecular organization of the y5 TCR is well advanced, current knowledge of function and specificity of the y5 T cell subset is poor. There- fore it appeared rather timely to bring together...