PGK1 and viral infectious disease: Given that the nuclear localisation and phosphorylation of β-catenin at Ser552 are prerequisites for its transcriptional activation [46, 47], the observed decrease in nuclear p-β-catenin (S552) protein levels due to PGK1 knockdown supports our findings that the PGK1-specific inhibitor NG52 inhibits β-catenin-dependent transcriptional activity stimulated by virus infection (Figure 8C).