The advances that led to cost-efficient genome sequencing cannot bring significant benefits in medical care and public health unless genetic data interpretation is facilitated. Essentially, the mainstreaming of genetics within healthcare and the realisation of their transformative potential is increasingly be-coming an information systems’ problem of providing adequate decision support and enabling data sharing. However, providing this support is far from straightforward as data governance in the field has been the subject of contestations between actors committed to finding ways for pooling all availa-ble data and actors advocating restrictive approaches. In this paper we analyse the tensions around the governance of genetic data related to two genes which influence humans’ susceptibility to breast and ovarian cancer (BRCA1 and BRCA2). Our research adopts a process approach that follows the evolution over time and draws theoretically from the Commons literature. Our findings show how “exclusion” and “subtractability” are not external data properties but sociotechnical achievements that are still in the making. Hence, aiming to handle genetic data as indisputably common goods or simply setting-up infrastructures with the expectation that they will be used, is futile. Instead, an effort that entails combining new technological potentialities with regulatory provisions is required.