Dual-specificity phosphatase 6 (Dusp6)-deficiency enhances baseline colon barrier integrity and confers amelioration of dextran sulfate sodium (DSS)-induced colonic injury. DUSP6 is a phosphatase, and therefore it is plausible that DUSP6 knockout alters the phosphorylation status of other proteins. To access the protein phosphorylation landscape and functional network in DUSP6 deficient Caco-2 cells, we applied phosphopeptide enrichment and isobaric labeling strategies with MS-based proteomics, and identified 1323 phosphorylation sites on 580 phosphoproteins.