“One of these functional proteins is a cysteine protease referred to as the main protease (Mpro, also called 3CLpro and nsp5). “ Quote from a different articles which mention out compound quit a bit.
“Therefore, the continued development of therapeutic and prophylactic countermeasures to potentially deadly coronaviruses is warranted. The coronaviral proteases, papain-like protease (PLpro) and 3C-like protease (3CLpro), are attractive antiviral drug targets because they are essential for coronaviral replication. Although the primary function of PLpro and 3CLpro are to process the viral polyprotein in a coordinated manner, PLpro has the additional function of stripping ubiquitin and ISG15 from host-cell proteins to aid coronaviruses in their evasion of the host innate immune responses.” Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5896749/.