ISTM, Medical School, Keele University at the Leopold Muller Arthritis Research Centre, RJAH Orthopaedic Hospital, Oswestry, Shropshire, SY10 7AG, UK, HelenL.smith@rjah.nhs.uk.
Upon the discovery of RANK, RANKL and OPG in the late 1990s, their importance in the maintenance of the skeletal structure and their dramatic role in bone disease were largely unexpected. In recent years the understanding of these proteins, in particular their regulation, has greatly increased. This review aims to bring the interested reader up to date with the latest news and views on the mechanisms controlling bone resorption in normal and pathological conditions.