TEC (tec protein tyrosine kinase) is a non-receptor tyrosine kinase that functions as a critical signal transducer in adaptive immune responses and hematopoietic cell signaling 1. TEC plays a redundant role to ITK in regulating T-cell development and function, and is required for TCR-dependent IL-2 gene induction through phosphorylation of downstream substrates like DOK1 1. In B cells, TEC cooperates with BTK in B-cell receptor signaling by phosphorylating STAP1, contributing to B-cell development and activation 1. Beyond immune signaling, TEC participates in integrin-mediated signaling in platelets and regulates cytokine production in mast cells 1. TEC also mediates myeloid cell growth and differentiation through activation by granulocyte colony-stimulating factor, and cooperates with JAK2 in cytokine-driven FOS transcription activation 1. Additionally, TEC regulates FGF2 unconventional secretion through phosphorylation and participates in hepatocyte proliferation and liver regeneration via HGF-induced ERK signaling 1. The kinase's multi-functional role in immune regulation, cytoskeletal reorganization, and tissue regeneration underscores its importance in cellular signaling networks across multiple biological contexts.