The present invention relates to compounds and compositions for expanding the number of CD34+ cells for transplantation. The invention further relates to a cell population comprising expanded hematopoietic stem cells (HSCs) and its use in autologous or allogeneic transplantation for the treatment of patients with inherited immunodeficient and autoimmune diseases and diverse hematopoietic disorders to reconstitute the hematopoietic cell lineages and immune system defense.本發明係關於用於增加CD34+細胞之數目以供移植的化合物及組合物。本發明進一步關於一種包含增加造血幹細胞(HSCs)的細胞群體及其在自體移植或同種異體移植之用途,其係用於治療患有遺傳性免疫缺乏與自體免疫疾病及各種造血障礙之患者以恢復造血細胞譜系及免疫系統防禦能力。