Other factors, such as hypoxia inducible factor 1 (HIF-1) [23,24], heme oxygenase (HO) [25], transforming growth factor-beta 1 (TGF-β1) [26], nuclear factor kappa B (NF-κB) [27] have also been reported to play important roles on COVID-19. Here, TGFB1 is linked to COVID-19.