Late at night on May 7, OpenAI leader Sam Altman made a surprising announcement: He’s offloading major parts of his job to a new partner: Instacart CEO Fidji Simo. In a significant structural change, Altman says that Simo will be OpenAI’s new CEO of Applications, and will oversee the company’s efforts to build AI-powered products and services.

The Instacart CEO told Fortune the U.S. healthcare system is not well-suited to treat rare and complex diseases, which is a major opportunity for AI.

WASHINGTON (AP) — OpenAI CEO Sam Altman and executives from Microsoft and chipmaker Advanced Micro Devices testified on Capitol Hill about the biggest opportunities, risks and needs facing an industry which lawmakers and technologists agree could fundamentally transform global business, culture and geopolitics.