The First International Conference on HLA-G, held in 1998, led us to the co
nclusion that HLA-G is a tolerance molecule from the major histocompatibili
ty complex (MHC) that plays an important role in maternal-fetal tolerance a
nd probably in tumours and transplantation. The Second International Confer
ence on HLA-G* focused on the pathophysiology of HLA-G and was extended to
HLA-E and HLA-F.