Enables protein-macromolecule adaptor activity. Acts upstream of or within T cell activation; negative regulation of B cell apoptotic process; and negative regulation of mitochondrial depolarization. Located in cytosol and mitochondrion. Is expressed in spleen and thymus. Orthologous to human HSH2D (hematopoietic SH2 domain containing). [provided by Alliance of Genome Resources, Apr 2022]