QQ culture medium of Stem Line II (Sigma‐Aldrich, St. Louis, MO) contained the 5 human recombinant proteins: stem cell factor (SCF); thrombopoietin (TPO); Flt‐3 ligand; vascular endothelial growth factor (VEGF); and interleukin (IL)‐6. Then, isolated PBMNCs were cultured for 7 days at the cell density of 2×106 cells/2 mL QQ culture medium per well of 6‐well Primaria tissue culture plate (BD Falcon; BD Biosiences, San Jose, CA). Cell density in QQ culture was corresponded to the approximate density of 1×106 MNCs in 1 mL of PB. Culture well plates and the contents of QQ culture medium are listed in Tables 1 and 2.