part_of part of part of lacks_plasma_membrane_part has plasma membrane part develops_from develops from develops from pro-T cell DN1 thymic pro-T cell DN1 thymic pro-T-lymphocyte DN1 thymic pro-T-cell DN1 thymic progenitor T cell preT.DN1.Th double negative 1 DN1 thymocyte DN1 thymic pro-T lymphocyte A pro-T cell that has the phenotype CD4-negative, CD8-negative, CD44-positive, and CD25-negative. early T lineage precursor CD4 molecule T-cell surface glycoprotein CD8 alpha chain CD44 molecule interleukin-2 receptor subunit alpha protein-containing material entity thymus