Based on his critique of the early case-control study of smoking and lung cancer by Mueller, Morabia questions the priority that has been assigned to this research. I examine Morabia's approach to retrospectively assess quality and question its general applicability and replicability. By citation analyses, the case-control studies published in the 1950s have had far greater impact. Morabia's commentary points to the complexity and subtlety of re-interpreting older literature.