Low arginine levels may allow cancer cells and viruses to evade the immune system. This occurs by reducing the production of a crucial cellular warning protein, which is important for signaling an immune response. Research in mice demonstrated that arginine-rich diets led to fewer colon tumors. They also resulted in milder viral infections. These findings suggest that a simple arginine supplement could possess powerful therapeutic potential. It could thus enhance the immune system's ability to fight cancer and viruses. This represents a promising discovery for future treatment strategies.