DOK proteins are enzymatically inert adaptor or scaffolding proteins. They provide a docking platform for the assembly of multimolecular signaling complexes. DOK4 functions in RET-mediated neurite outgrowth and plays a positive role in activation of the MAP kinase pathway (By similarity). Putative link with downstream effectors of RET in neuronal differentiation. May be involved in the regulation of the immune response induced by T-cells. Interacts with RET and TEK/TIE2. Interaction with RET is mediated through the PTB domain and requires phosphorylation of RET 'Tyr-1062' (By similarity). Widely expressed. High expression in skeletal muscle, heart, kidney and liver. Weaker expression in spleen, lung and small intestine, brain, heart and. Expressed in both resting and activated peripheral blood T-cells. PTB domain mediates receptor interaction. Phosphorylated on tyrosine residues in response to insulin, IGF1 or RET stimulation. Belongs to the DOK family. Type B subfamily.