DOK7 (Downstream of kinase 7) is a 55 kDa member of the DOK family of cytoplasmic adaptor proteins. It links the acetylcholine receptor and the receptor tyrosine kinase MuSK in skeletal and cardiac muscle. Mutations can cause familial myasthenic syndromes. DOK7 contains pleckstrin homology, phosphotyrosine-binding and SH2 domains, and a C-terminal nuclear export signal. Multiple isoforms exist.