SRF (serum response factor) is a transcription factor that binds to serum response elements and regulates gene expression in multiple cellular processes. SRF functions through complex formation with different co-activators: it partners with myocardin-related transcription factors (MRTF-A) to control cytoskeletal gene expression and respond to actin dynamics 1, and forms ternary complexes with ELK-1 proteins for alternative gene regulation 2. In vascular smooth muscle cells, SRF controls phenotypic switching between contractile and synthetic states, with SUMOylation at lysine 143 modulating its nuclear localization and complex formation 3. The SRF-MRTF-A pathway is crucial for cardiomyocyte maturation, regulating sarcomere assembly and mitochondrial metabolism 1. SRF also promotes angiogenesis through calcium-dependent phosphorylation and VEGFR2 transcription 4, and facilitates cancer cell metastasis via β1-integrin regulation 5. Clinically, SRF dysregulation contributes to cardiovascular diseases through altered vascular remodeling 3, liver fibrosis through MRTF-A complex activation 6, and pediatric soft tissue tumors via gene rearrangements 7. These findings establish SRF as a central regulator linking cytoskeletal dynamics to transcriptional programs in development and disease.