Arizona researchers identify gene molecule that could explain the wide range of COVID-19 outcomes As mysteries of why some people get sick with COVID-19 and die, and others have mild cases continue, Arizona researchers think they may have found one reason why. Author: Colleen Sikora Updated: 7:46 PM MST December 24, 2020 Over the past nine months of the COVID-19 pandemic, scientists have learned a lot about the virus, but one mystery still plaguing doctors and patients is why some people have mild cases, while others become so sick they die. While COVID-19 has such a wide range of outcomes, Arizona scientists at TGen think it could be a molecule that factors into how sick someone gets.