In 2025, we attended the 19th International Congress of Immunology, hosted by the International Union of Immunological Societies, in Vienna, Austria, and recorded daily episodes discussing highlights of the conference. Here is the first of five special episodes from the meeting. Brenda and Jason discuss sessions on colon cancer organoids and stable induced regulatory T cells. They also cover presentations from the IUIS Rising Star Awardees and Dr. Yasmine Belkaid’s talk on maternal physiology.