For decades, cyclosporin A has served medicine as a tool for quieting the immune system — yet it has long harbored a paradox, demonstrating antiviral properties that seemed to contradict its very purpose. Researchers have now traced this contradiction to its cellular roots, revealing that the drug simultaneously disrupts mitochondrial architecture and impairs the cell's own housekeeping machinery, allowing fragments of double-stranded RNA to accumulate and trigger a natural antiviral alarm system known as the RIG-I pathway. The discovery, emerging from studies of human airway cells and enginee