Acts upstream of or within humoral immune response and positive regulation of natural killer cell mediated cytotoxicity. Predicted to be located in cytoplasm. Is expressed in retina. Used to study X-linked lymphoproliferative syndrome 1. Human ortholog(s) of this gene implicated in X-linked lymphoproliferative syndrome 1. Orthologous to human SH2D1A (SH2 domain containing 1A). [provided by Alliance of Genome Resources, Apr 2022]