Abnormally low arginine levels have been linked to several diseases, including colon cancer. In 2023, his team reported that depriving colon cancer cells of arginine caused them to accumulate more mutations. For the new study, Wu examined whether shifts in arginine levels caused by diet or disease could alter gene expression. They display foreign or abnormal proteins to T cells, which then recruit other immune cells to respond to the threat. "Qiushuang's findings illuminate how poor diet and aging -- during which arginine levels naturally decline -- could create the perfect storm for the initiation of colon cancer.