KLF3 (Krüppel-like factor 3) is a zinc finger transcription factor that regulates gene expression across multiple biological processes through sequence-specific DNA binding. KLF3 functions as a transcriptional regulator in muscle gene expression, where it synergizes with serum response factor (SRF) to transactivate muscle-specific genes including muscle creatine kinase, myosin heavy chain, and skeletal alpha-actin 1. In hematopoiesis, KLF3 cooperates with other KLF family members to regulate inflammatory responses in macrophages and myeloid cell function 2. The protein exhibits context-dependent roles in disease pathogenesis. In cancer, KLF3 demonstrates oncogenic properties by promoting tumor growth and metastasis through activation of WNT/β-catenin signaling in gastric cancer 3 and colorectal cancer 4, while showing decreased expression in breast cancer 5. KLF3 also contributes to pathological fibrosis by transcriptionally activating DDAH2 in chr4 kidney disease 6. Additionally, KLF3 regulates CD8+ T cell metabolism in tumor microenvironments through modulation of glycolysis pathways 7. These findings establish KLF3 as a versatile transcription factor with significant roles in muscle development, immune regulation, and disease progression.