This paper reviews the Seventh Human Leucocyte Differentiation Antigen (HLD
A7) workshop. Due to the limitations of "blind" antibody screening, which h
ad been evident at the previous meeting in 1996, participants at HLDA7 adop
ted a more selective approach to the choice of antibodies by identifying ne
w CD specificities. This resulted in the addition of more than 80 new CD sp
ecificities. Plans for the eighth and subsequent workshops are also preview
ed.