The main protease, which cleaves the viral polyproteins, releasing the matured proteins. Nsp5 also cleaves host proteins, which affects viral infections (143). Nsp5 targets ATG1/ULK1 kinase and p62 cargo receptor of the autophagy pathway to disrupt autophagy (144–146). The activity of Nsp5 is affected by autophagy through ubiquitination by the host Parkin E3 ligase (147). This evidence concerns the gene SPECC1 and viral infectious disease.