In this paper we investigate how data openness can be made possible in communal settings. We adopt a utility perspective that foregrounds the use value of data, conceptualizing them as "goods."On the basis of this conceptualization we explore 2 key goods' attributes: subtractability and exclusion. Our theoretical basis is built upon concepts from the theory of the commons, power theorizing, and notions related to data and information. Empirically, we investigate openness in the genetics domain through a longitudinal study of the evolving communal infrastructure for data related to 2 genes influencing women's susceptibility to breast and ovarian cancer (BRCA1 and BRCA2). We follow the continuously shifting "topology" of the BRCA information infrastructure and trace the multiple repositories that are put in place and the different arrangements for data collection, curation/quality assurance, access, and control that are tried out. In our analysis, we illustrate the actors' strategies for curbing the subtractability and exclusion attributes of data. We then propose a theoretically informed and empirically grounded framework that can guide understanding and action taking to enable data openness. The advent of genetic testing for clinical purposes and the rapid development of sequencing technologies led to an exponential growth of genetic data. These data are valuable resources for both researchers and clinicians. ResearchersThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.