Abstract
With the death of Charles Weissmann, molecular biology has lost of one of its most productive, outstanding, and critical representatives. A molecular biologist who became famous through his ground-breaking discoveries, as well as his scientific presentations, which always included “little stories,” used to illustrate the main points of his talks in a persuasive and amusing fashion. He will be remembered for unraveling the replication of RNA bacteriophages; for developing the first example of targeted mutagenesis, using viral RNA; for cloning the first interferon gene; for his decisive contributions to the origin and pathogenic effects of prions; and for the superb quality of his experimental work and mentorship.