MLX (MAX dimerization protein MLX) is a basic-helix-loop-helix leucine zipper transcription factor that functions as a heterodimeric partner with ChR17/Mondo and other proteins, recognizing the core DNA sequence 5'-CACGTG-3' 1. As a key component of glucose-responsive gene regulation, MLX heterodimerizes with ChR17 to form a heterotetramer that binds tandem carbohydrate-responsive elements (ChoRE) containing adjacent E-boxes 2. MLX phosphorylation by casein kinase 2 and glycogen synthase kinase 3 is essential for heterotetramer stabilization and transcriptional activity 2. The ChR17-MLX complex acts as a nutrient sensor, coupling intracellular sugar and metabolite levels to coordinate carbohydrate and lipid metabolism 23. Loss of ChR17-MLX function causes sugar intolerance and metabolic dysregulation 3. In humans, MLX knockdown decreases hepatic de novo lipogenesis while increasing fatty acid oxidation and improving insulin sensitivity 4. In cancer contexts, super-enhancer-driven MLX upregulation promotes metabolic reprogramming and osteosarcoma growth by regulating the cystine transporter SLC7A11 to maintain redox balance and prevent ferroptosis 5. Additionally, genetic variants in MLX associate with altered plasma triglycerides, insulin levels, and hepatic DNL in humans 4, and MLX variants link to brain iron homeostasis with implications for neurodegenerative diseases 6.