Carmofur (HCFU) is a rat recombinant acid ceramidase inhibitor with an IC50 of 29 nM. Carmofur is also a protease inhibitor of SARS-CoV-2 main protease (Mpro), fatty acid amide hydrolase (FAAH) and N-acylethanolamine acid amidase (NAAA). Carmofur has anti-cancer, anti-inflammatory and anti-virus activities, and can be used for the study of COVID-19 and acute lung injury (ALI)[1][2][3].