The non-classical human leukocyte antigen (HLA) Class I molecule HLA-G is best known for its tolerogenic function at the maternal–fetal interface, where it protects the fetus from destruction by the immune system of its mother. Yet, HLA-G has been the topic of intense investigations and its functions reach much further than originally believed. International conferences on HLA-G have taken place every 3 years since 1998, and the Sixth International Conference on HLA-G, that took place in Paris in July 2012. It counted 180 attendees from 28 countries, 35 speakers in plenary sessions, and 63 presentations of research in symposia and poster sessions, bringing new insight in HLA-G research. Here we summarize the major advances on the function and nature of HLA-G molecule that were reported, with particular interest on the findings in new mechanisms of action through regulatory cells, its relevance in cancer as well as in the molecular structure and functions of HLA-G, which are key for its clinical application.