T-cell receptor gene rearrangements in gamma delta T cells have been t
he subject of intense molecular investigations. This year, much has be
en learned about the mechanisms controlling this process. However, the
specificity and function of gamma delta T cells still remains enigmat
ic. The application of molecular technology including the availability
of mutant mice lacking defined T-cell populations and immunologically
relevant surface proteins is beginning to provide answers as well as
some surprises.