Epigenetics is a new dialogue between disciplines, and also between different kinds of data. Indeed, institutions gathering what is commonly called “big data”, be they private or public (social security) are major actors in the field. Biobanks, that gathers together collections very different in kind, such as tissues, medical and sociodemographic data, are flourishing. Birth cohorts, based on representative samples of fetuses followed from conception to the 20th anniversary of the person they became, are also developing. This proliferation of new data is in itself a social event with specific motives, means, and consequences that ought to be studied in Epidapo.