Even if the role of the two MMPs in the pulmonary disease of COVID-19 patients is still not completely defined, the pharmacological inhibition of MMP3 was suggested as a potential therapeutic option in COVID-19 patients with ARDS8, while another paper suggested the repositioning therapy with aprothinin, an aspecific protease inhibitor, in COVID-19 patients with severe lung injury17. Here, MMP3 is linked to COVID-19.