Predicted to enable identical protein binding activity and transmembrane signaling receptor activity. Predicted to be involved in cell surface receptor signaling pathway and positive thymic T cell selection. Predicted to be integral component of membrane. Predicted to be part of alpha-beta T cell receptor complex. Predicted to be active in external side of plasma membrane. Human ortholog(s) of this gene implicated in immunodeficiency 19 and severe combined immunodeficiency. Orthologous to human CD3D (CD3d molecule). [provided by Alliance of Genome Resources, Apr 2022]