Our earlier X-ray crystallographic studies of drug-DNA complexes at the University of Rochester have led to an understanding of the dynamic structural mechanism that allows planar drugs and dyes to intercalate into DNA. This same mechanism explains the physical basis of DNA "breathing" and "melting" -- deepening our understanding of the initiation, elongation and termination of RNA synthesis by the RNA polymerase accompanying transcription. Finally, it explains how actinomycin interferes with DNA transcription -- and in so doing -- suggest that trace amounts of actinomycin given over an extended period of time be a powerful anticancer regimen in the treatment of many different kinds of cancer.