Representative flow cytometric analysis of bone marrow, peripheral blood, peritoneal cells, and spleen from NOG mice after HSC transplantation. Human mast cell and basophil development from the transplanted human CD34⁺ cells were identified as CD203c/Kit (CD117) double-positive cells and CD203c/IL-3 receptor α-chain (CD123) double-positive cells, respectively, in human CD45⁺ cells. The percentage of human CD45⁺ cells differed depending on the transplanted cord blood-derived cells, but the proportion of CD203c/Kit double-positive cells and CD203c/CD123 double-positive cells in reconstituted human CD45⁺ cells was similar in 4 independent experiments.