A forgotten story of monozygotic twins reared apart is described. The pair, born in 1941 in Fribourg, Switzerland, were separated due to switch-baby incident in the hospital. This caused one twin to be raised as a singleton by an unrelated family, and the other twin to be raised as a ‘dizygotic’ twin with an unrelated child. This is followed by reviews of recent twin research and case studies of X-inactivation and hemophilia, breast reconstruction, chimerism and life histories. The final section of the article includes human interest pieces on academic twins, dating twins, transsexual twins and athletic twins.

Aunique case of artificially conceived twins is described. The infants involved are unrelated to one another, as well as to the mother who carried them. The question of whether these individuals meet scientific criteria for being twins is considered, as is the issue of whether their parents are really parents of twins. Next, the International Society for Twin Studies acknowledges the life and work of its late esteemed colleague, Dr Robert Derom. His professional accomplishments on behalf of twins and twin research will be remembered, as will his helpfulness and generosity to fellow investigators. This tribute to Dr Derom is followed by reviews of new research on the pathophysiology of the twin transfusion syndrome and the use of discordant MZ twins (co-twin control) in behavioral research. The final section provides a review of the athletic talents of two sets of MZ twin tennis players, and the creative skills of a set of MZ twin designers.