In a significant shake-up within the National Institutes of Health (NIH), five institute directors and numerous lab heads have been ousted, marking what some are calling one of the darkest days for the agency. The firings extend beyond the NIH, affecting federal health agencies and many in leadership roles. Notably, a prominent doctor involved in award-winning Parkinson’s research has also been purged. Senior NIH leader Tara Schwetz, who played a key role in the establishment of ARPA-H, has been placed on leave, while the acting NIH director has dismissed five neuroscientists from advisory boards. The agency is also removing certain external scientific advisers who evaluate its research, indicating a deep restructuring amid these massive staff layoffs.