xAI Cofounder Steps Back After Lyme Diagnosis

Greg Yang, a cofounder of Elon Musk’s xAI, said Tuesday on X that he will move immediately into an informal advisory role after being diagnosed with Lyme disease. Yang said symptoms began after an illness in early 2025, citing persistent fatigue that reduced his energy and creativity; he joined xAI in June 2023 and the change follows other cofounder departures last year.