SGK3 (threonine-protein kinase 3) is a functional kinase we identified previously with the capacity to promote cardiomyocyte proliferation and cardiac repair after myocardial infarction. However, the upstream signals regulating SGK3 are still unknown. Based on the quantitative proteomics data and pulldown assay, we identified cyclin-dependent kinase 9 (CDK9) as a novel therapeutic target in regeneration therapy.