This image provided by Ana-Maria Cujba shows blood vessels in a portion of the human small intestine, March 21, 2024. (Ana-Maria Cujba/Wellcome Sanger Institute via AP)

This image provided by Nathan Richoz shows a T cell aggregate in a human trachea biopsy on July 12, 2021, at the University of Cambridge in Cambridge, England. (Nathan Richoz/Clatworthy Lab/University of Cambridge via AP)