Effect of matrine and oxymatrine on proliferation and expression of Stat3 and Stat5 in SMMC-7721 cell line Effect of angelica polysaccharides co-erythropoietin on JAK2/STAT5 signal transduction pathway in hematopoietic stem/ progenitor cells Effect of angelica polysaccharides co-erythropoietin on JAK2/STAT5 signal transduction pathway in hematopoietic stem/ progenitor cells