The expression of CD4 , a marker for T-derived lymphoid cells , was not significantly different in serum-free medium .
the expression of cd4 , a marker for t-derived lymphoid cells , was not significantly different in serum-free medium .
O O O B-protein_molecule O O O O B-cell_type I-cell_type I-cell_type O O O O O O B-other_organic_compound I-other_organic_compound O