CROI 2025: Summary of Basic Science Research in HIV.

The 2025 Conference on Retroviruses and Opportunistic Infections (CROI) in San Francisco maintained its existing format with a combination of plenary lectures, workshops, oral and poster abstract sessions, themed discussions, and interactive symposia to deliver the latest advances in HIV/AIDS research to the approximately 4000 delegates in attendance. The conference featured a comprehensive collection of presentations addressing the molecular biology of HIV-1, with the basic virology track offering mechanistic insights into viral replication, immune evasion, and host-pathogen interactions. CROI showcased a range of innovative approaches to decipher and target the latent reservoir. From high-resolution lineage tracking in nonhuman primates to dissection of chromatin landscapes and latency regulatory circuits, studies presented at this year's meeting underscored the complexity of HIV persistence and the need for multidimensional intervention strategies. Selected abstracts are high-lighted, emphasizing mechanistic insights, methodologic innovations, and therapeutic implications. As with prior renditions of the conference, CROI continues to set the standard for engagement of early career investigators. Sessions such as the Scott M. Hammer Workshop for New Investigators and Trainees provide an effective forum for orientation to the various thematic areas covered at CROI.