This brief review has focused on data collections done on essentially unselected twin pairs. Over the years, many twins have been invited to participate in selected sub-studies for more intense assessments, but these are not described in detail here. Likewise, there have been more than 300 peer-reviewed publications after 2006. A dozen PhDs have been completed since 2006 under my supervision and many more as part of other research projects, to which the twin data has contributed at least in part. In 2013, we start a Marie Curie Initial Training Network in Epigenetics (EPITRAIN), which will offer training to three PhD students based in Helsinki, and many more through our other European partners. The numerous national and international scientific and researcher training collaborations indicate the continued value of large follow-up studies of twins and their family members. These studies also highlight the representativeness of adult twins, as shown here in our mortality analysis. The newest data collections will increase the informativeness and uniqueness of the cohort data, permitting more detailed analyses of factors predicting changes and stability of health related behaviors, health status and other outcomes of interest over decades of follow-up.
