One such antibiotic came from a rod-shaped microbe called Actinomyces. Waksman called it actinomycin D. An enormous molecule shaped like an ancient Greek statue, with a small, headless torso and two extended wings, actinomycin D was later found to work by binding and damaging DNA. It potently killed bacterial cells—but unfortunately it also killed human cells, limiting its use as an antibacterial agent. But a cellular poison could always excite an oncologist.
