USP20 and cardiac hypertrophy: These results suggest that STAT3 binds to USP20 through its CCD domain, which is known to regulate the phosphorylation and nuclear translocation of STAT3 via allosteric regulation of SH2.[39] As for the ubiquitination sites on STAT3 involved in pathological cardiac hypertrophy have not been reported, we utilized affinity‐based ubiquitin peptide enrichment ubiquitomics to investigate the specific ubiquitination sites on STAT3 modulated by USP20 (Figure S9A, Supporting Information).