Scientists at the National Institutes of Health demonstrated a promising step toward using a person's own immune cells to fight gastrointestinal cancers in a paper in Nature Medicine on Tuesday, the same day the agency was hit with devastating layoffs that left many NIH personnel in tears. The treatment approach is still early in its development; the personalized immunotherapy regimen shrank tumors in only about a quarter of the patients with colon, rectal and other GI cancers enrolled in a clinical trial. But a researcher who was not involved in the study called the results "remarkable" because they highlight a path to a frustratingly elusive goal in medicine " harnessing a person's own immune defenses to target common solid tumor cancers. Until now, cell-based immunotherapy has worked mainly on blood cancers, such as leukemia, but not the solid cancers that seed tumors in the breast, brain, lungs, pancreas and GI tract.