Nirmatrelvir (PF-07321332) is a potent and orally active SARS-CoV?3C-like protease (3CLPRO) inhibitor. Nirmatrelvir (PF-07321332) targets to the SARS-CoV-2 virus and can be used for COVID-19 research.IC50 & Target:IC50: 3CLPROIn Vitro:3CLPRO is responsible for cleaving polyproteins 1a and 1ab of SARS-CoV-2.1.?Without the activity of the SARS-CoV-2 3CLPRO, nonstructural proteins (including proteases) cannot be released to perform their functions, inhibiting viral replication.