RIOX2 and COVID-19: Although we cannot distinguish the question of whether mdig promoted fibrosis or fibrosis caused a higher expression of mdig in human lung tissues, based on previous mouse model with mdig knockout and the fact that mdig is a master regulator of inflammation 17-19, we believe that mdig is a critical driving factor for the development of lung fibrosis associated with some disease conditions, such as COVID-19, chronic bronchitis, pneumonia, and cancer.