An overview of the nature and success of organ transplantation in monozygotic (MZ) twins is presented. Recent timely examples demonstrate the unique donor–recipient relationship shared by MZ co-twins. Next, a recent analysis of MZ co-twin differences in the epigenetic profile and associations with differences in life history factors is presented. This work has been the focus of considerable attention by scientists and the media. The final section of this column summarizes information and events concerning twins' longevity, screen careers, older parenting of twins and the origin of the word ‘twin’.