PPARD (peroxisome proliferator-activated receptor delta) is a transcription factor, a protein that switches on genes controlling how cells burn fat for energy. Cancer cells use PPARD to support their own growth, but researchers at Cold Spring Harbor Laboratory reported in Nature Immunology in October 2026 that activating PPARD inside immune cells instead made them better at burning fat and attacking tumors.
In mice and in lab experiments with human cancer cells, CAR T cells (engineered immune cells) with PPARD activated slowed or stopped tumor growth in colorectal cancer, and the team saw promising results in breast cancer, ovarian cancer, and melanoma as well. The approach has not yet been proven in patients.
Image: Killer T cells surrounding a cancer cell. National Institutes of Health, public domain, via Wikimedia Commons.