TAB1 is a critical adapter protein that functions as a molecular hub in innate immune signaling. Its primary role involves activating MAP3K7/TAK1 kinase through direct association with its catalytic domain, triggering autophosphorylation and full kinase activation 12. TAB1 similarly associates with and activates MAPK14 (p38α), while MAPK14 phosphorylates TAB1 in a feedback inhibition mechanism 34. TAB1 acts as a scaffolding protein recruiting regulatory proteins to the TAK1 signaling complex 5. Mechanistically, TAB1 serves as a protein serine/threonine kinase activator and possesses inherent phosphatase activity characteristic of PP2C phosphatases 6. TAB1 responds to stimulation by Toll-like receptor ligands, TNFα, and IL-1β, activating downstream NF-κB and MAPK cascades essential for proinflammatory cytokine production 7. Disease relevance spans sepsis, where TAB1 is regulated via NLRP6/TRIM21-mediated K48-linked polyubiquitination, affecting platelet thrombosis and NET formation 8; nasopharyngeal carcinoma, where TAB1 mediates ferroptosis resistance 9; tuberculosis, where TAB1 complex formation regulates antimicrobial peptide expression 10; and kidney disease, where TAB1 facilitates macrophage infiltration via TRAF6-mediated K63-ubiquitination 11. Under metabolic stress, GFAT1-mediated TAB1 glutamylation sustains p38 activation promoting cancer cell survival 12. These diverse regulatory mechanisms position TAB1 as a convergence point for inflammatory, metabolic, and stress-response signaling.