The scaffolds (with supportive cells) were subcutaneously (s.c.)implanted in NSG mice in combination with intraperitoneal (i.p.)application of up to 1 × 107 HS5-CD40L-IL4 or HS5-CD40L-IL4-IL21 cells (not mitotically inactivated) to create two niches for CLL engraftment, i.e., intra-scaffold and in peritoneal cavity. The gene discussed is IL21; the disease is B-cell chronic lymphocytic leukemia.