Book excerpt: The stories presented in this report illustrate how improved collaboration among RTB centers is making a real difference. This includes harnessing the potential of genomics to accelerate the development of improved RTB varieties, facilitating collaborative responses to critical crop diseases and improving postharvest options. During its second year, the CGIAR Research Program on Roots, Tubers and Bananas (RTB) expanded its geographic reach and its network of partners while launching a series of collaborative initiatives aimed at resolving the most serious constraints faced by smallholder farmers growing RTB crops. While this work was initiated within a framework of seven disciplinary themes, RTB started a process to transition from an output-focused research agenda to one based on outcomes and impacts.