The UCSF International Traineeships in AIDS Prevention Studies (ITAPS) program will advance global research in HIV prevention and implementation science by building the capacity of scientists in low- and middle-income countries (LMIC) to operate independently or in collaboration with developed country scientists. Although an AIDS-free generation is within reach, the burden of HIV/AIDS in LMIC remains high, and there will continue to be a need for more well-trained prevention scientists for the foreseeable future. Armed with an intimate knowledge of their own culture and settings, LMIC investigators can design effective studies, find and gain the trust of hard-to-reach populations, launch informed prevention campaigns and disseminate the findings to key stakeholders. Since 1988, ITAPS has had a substantial impact in building capacity in HIV/AIDS prevention research by training 243 early career scientists from 46 countries. ITAPS is built around a model of long-term mentoring as early career investigators conduct innovative research and prepare scientific manuscripts and grant applications as principal investigators. In this competitive renewal, we will focus on harnessing the talent and promise of our global ITAPS alumni network as an efficient and sustainable route to prepare the next generation of prevention scientists from LMIC. We propose three strategies to leverage the strengths of our global ITAPS alumni network. The first strategy is a Mentoring-of-Mentors Program. We will select 15 of our most productive alumni to mentor promising early career scientists at their home institutions, countries or regions. These alumni will participate in a blended program of distance-learning and in-person training at UCSF to: (a) develop their mentoring skills; (b) serve as faculty for our successful Scientific Manuscrit Writing Program; (c) implement scientific writing training in their home countries and regions; and (d) foster "South-South" HIV research and training collaborations. The second strategy involves recruiting 50 new trainees for our Scientific Manuscript Writing Program, led by our newly trained ITAPS alumni mentors. These trainees will be drawn from two groups: ITAPS alumni who designed pilot research projects at UCSF and who are ready to write up the results of their studies, and other early career scientists recruited from LMIC. The third strategy will be an intensive Grant Writing Program in which one to two ITAPS alumni will be selected in each grant year to prepare and submit NIH grant applications under the mentorship of our UCSF ITAPS faculty. For each of these activities, we will select trainees whose research projects and interests are closely aligned with current NIMH and OAR priorities. The proposed network-focused approach is the natural next step in the evolution of the ITAPS program, expanding its reach and impact, enhancing its sustainability, and nurturing a cadre of global HIV researchers and mentors.