In this modular case study, students discover how the cystic fibrosis transmembrane conductance regulator (CFTR) membrane channel protein affects multiple physiological systems. The case is divided into an introductory narrative followed by five sections covering different physiological topics: genetics, cell physiology, respiration, reproduction, and microbiology. Instructors may choose to use the five parts collectively, in any order, or individually, depending upon the topics covered in their course or unit. In the introductory section, students are given background information about a family and their young son, “Tyler,” who has cystic fibrosis (CF). The genetics section presents the role of recessive inheritance and how different mutations in the CFTR protein lead to varying severity of disease while the cell physiology section examines the dysfunction of the CFTR protein. The effects of sticky mucus resulting from CFTR dysfunction is explored in the respiratory and reproduction sections. Finally, CF patients often experience recurrent or chronic respiratory tract infections and are monitored and treated carefully with antibiotics to mitigate lung function deterioration, information covered in the microbiology section. The case was developed for a physiology course in which students are following pre-medical, pre-nursing, or other allied health career paths.