Enables transmembrane receptor protein tyrosine kinase adaptor activity. Acts upstream of or within Ras protein signal transduction and transmembrane receptor protein tyrosine kinase signaling pathway. Predicted to be active in cytoplasm. Is expressed in heart; lung; lymph node; spleen; and thymus. Orthologous to human DOK2 (docking protein 2). [provided by Alliance of Genome Resources, Apr 2022]