The COVID-19 pandemic had a profound effect on the world, resulting in a dramatic loss of human lives. While the situation is now largely under control, there are patients who still suffer from the disease and have symptoms lasting for more than three months. The set of these symptoms has been linked to a condition called “long COVID,” which persists after an initial period of COVID-19 infection. While the condition is still under study, researchers in Japan have made a significant discovery in the fight against long COVID.