Abstract: MUC5B is a major component of mucus in the human airway and plays a significant role in removing pathogens and debris out of the lungs. However, a genetic variant in the MUC5B gene is enriched in a rare disease called idiopathic pulmonary fibrosis (IPF) which led to its discovery. It is still unknown why the variant is enriched in IPF. Interestingly however, while IPF remains rare even in those with the genetic variant, the variant is common in the northwestern region of the globe (about ~1/5 people have at least one variant). Why is this variant so common? Could it have a beneficial effect? In this talk, we use survival analysis techniques with data from the All of Us database to show that the MUC5B variant is protective against COVID-19 hospitalization, perhaps suggesting some protective effect against viral respiratory pathogens. Further results will suggest a trend toward a protective effect against all-cause mortality.