This "clicker case" was designed to develop students' ability to read and interpret information stored in DNA. Making use of personal response systems ("clickers") along with a PowerPoint presentation, students follow the story of "Jason," a student intern at the Centers for Disease Control & Prevention (CDC). While working with a CDC team in Mexico, Jason is the only person who does not get sick from a new strain of flu. It is up to Jason to use molecular data collected from different local strains of flu to identify which one may be causing the illness. Although designed for an introductory biology course for science or non-science majors, the case could be adapted for upper-level courses by including more complex problems and aspects of gene expression, such as the excision of introns.