Culture of human cord blood CD133⁺ cells in the presence of IGFBP2 or Angptl5 stimulates ex vivo expansion of SRCs. (A) Culture of 10⁴ cryopreserved human cord blood CD133⁺ cells was initiated in serum-free StemSpan medium supplemented with 50 ng/mL human SCF, 10 ng/mL human TPO, and 50 ng/mL human Flt3-L, together with 100 ng/mL human IGFBP2 or 500 ng/mL human Angptl5. Total cell numbers were counted during the 10 days of culture period. (B) Multilineage engraftment in NOD/SCID recipients that received a transplant of cultured progenies from 8000 initial CD133⁺ cells (n = 6-9). Lanes 1-4 show cells cultured in SCF, TPO, and Flt3-L; lanes 5-8, cells cultured in SCF, TPO, Flt3-L, and IGFBP2; lanes 9-12, cells cultured in SCF, TPO, Flt3-L, and Angptl5. *Value is significantly different from the value of the lane 1 cells. Student t test, P < .05.