MAFK (MAF bZIP transcription factor K) is a small Maf protein functioning as a context-dependent transcriptional regulator 1. As a basic region leucine zipper (bZIP) transcription factor, MAFK lacks a transactivation domain and acts as a transcriptional repressor when forming homodimers 1. However, MAFK functions as a transcriptional activator by heterodimerizing with Cap 'n' Collar (CNC) family proteins including NFE2L2/NRF2, NFE2L1/NRF1, and NFE2L3/NRF3, enabling their DNA binding to specific regulatory elements 1. MAFK also heterodimerizes with Bach proteins and competitively represses NF-E2 transcription factor activity 1. In disease contexts, MAFK serves as a signature transcription factor for iCMS3 molecular subtype colorectal cancers, contributing to distinct epigenetic and gene expression signatures 2. MAFK correlates with transcriptional repression in hepatocellular carcinoma contexts, particularly when paired with MAFF 3. MAFK polymorphisms have been associated with isoniazid-induced hepatotoxicity susceptibility by modulating antioxidant enzyme expression 4. Small MAFs including MAFK regulate mammalian stress response and detoxification pathways, linking them to diabetes, neuronal disorders, and carcinogenesis 5. The expression and activity of MAFK are tightly regulated at multiple regulatory levels, positioning it as a critical node in cellular transcriptional networks.