This month's theme "Knowledge translation in global health" offers an opportunity to highlight the overlooked but dramatic impact of social entrepreneurs in the health sector and to detail ways in which their knowledge, innovations and enterprise can add strength and utility to systems ripe for change. The global health sector and its corporate, academic, governmental and philanthropic partners are fully engaged in efforts to improve basic and applied research, deliver networks and resources for more timely and better care, and design more effective mechanisms to bridge the gaps between knowledge and practice. This is an ambitious agenda of growing urgency, with daunting challenges. Kwok-Cho Tang et al. provided the context, (1) noting that since the 1986 Ottawa Charter for Health Promotion new patterns of consumption and communication, urbanization, environmental changes and public health emergencies--along with accelerating social and demographic changes to work, learning, family and community life--have become critical factors influencing health. Over the same period, Ashoka: Innovators for the Public began a global search for individuals with ideas for changing systems to make them capable of bringing about vastly improved outcomes in education, human rights, environment, economic development, civic engagement and health. (2) Ashoka recognized these people as "social entrepreneurs" and led a change in the ways that foundations and other investors analyse opportunity and measure impact, that business schools prepare students for careers in the fast-growing citizen sector, and that corporate and community leaders create opportunities for meeting their goals. (3) Drawing on Ashoka's 25 years of experience with 1700 social innovators in 70 countries, including some 400 in the health sector, its Changemakers Initiative designed a global sourcing methodology--a mapping tool called a "mosaic"--that provides a scan of a particular field: a snapshot of its action principles likely to ensure success, its principal barriers to change, and a selection of mini-profiles of innovative practitioners. (4) The mosaic for health was the conceptual centrepiece of an online collaborative competition at Changemakers. (5) An open engagement with contestants brought together investors, policy experts, academics and citizen activists in a global process. "Cross-pollination" between sectors is desirable if sustained progress towards health for all is to be a reality, and cross-sectoral success stems from the ownership that develops when various stakeholders participate in developing action and policy. (6) Changemakers follows this model of collaboration and ownership by engaging health competition finalists and other key participants in policy and investment deliberations. The competition attracted 139 entries from 40 countries--a mix of organization size, growth stage, profit motivation and complexity. …