CREB1 (cAMP responsive element binding protein 1) is a phosphorylation-dependent transcription factor that activates gene expression by binding to cAMP response elements (CREs) in promoter regions 1. As a master transcription factor, CREB1 regulates diverse cellular processes including circadian rhythmicity, adipogenesis, and inflammatory responses 2. CREB1 activity is controlled through phosphorylation via multiple signaling pathways, including cAMP-dependent mechanisms and calcium/calmodulin kinase signaling 3. Mechanistically, CREB1 functions as a transcriptional hub controlling metabolic and inflammatory gene programs. It regulates endothelial barrier function through VE-cadherin transcription in response to cAMP signaling 1, controls neutrophil inflammatory phenotypes through CXCR4 expression 2, and modulates ferroptosis resistance via HMOX1 transcription 4. CREB1 also regulates mitochondrial homeostasis and apoptotic responses to environmental toxins 5. Clinically, CREB1 dysregulation is implicated in multiple diseases. Its activation promotes HPV oncogene expression in cervical cancer 6, supports castration-resistant prostate cancer growth through cholesterol metabolism 3, and enhances colorectal cancer progression via circRNA-mediated mRNA stabilization 7. CREB1 genetic polymorphisms interact with environmental exposures, including fluoride, to modify thyroid function in children 8. These findings suggest CREB1 as both a therapeutic target in cancer and a potential biomarker for environmental health outcomes.