Endogenous GATA-1 expression is inversely related to CCR5 expression in human CD34⁺ hematopoietic stem cells during DC differentiation. Purified and expanded primary human HSCs were cultured in stem cell media or DC-differentiating media and 2 endpoints were analyzed: (A) cell-surface CCR5 expression was assessed at the indicated time points via flow cytometry and (B) endogenous GATA-1 mRNA levels were determined via quantitative real-time PCR (see “Materials and methods”). The findings represent 2 experiments performed using stem cells isolated from independent umbilical cord blood samples