CD34⁺ cells express CAR. RNA extracts from isolated human CD34⁺ cells were subjected to 35 cycles of RT-PCR reaction coamplifying CAR¹⁸ and GAPDH (see Materials and Methods). For comparison, RNA from HUVEC (positive control) and from the human leukemic cell line KG1a (negative control) were included in this experiment. RT control was performed with RNA from CD34⁺ cells that were treated with RNAse H before RT-PCR. Two different samples of peripheral blood CD34⁺ cells (lanes 1 and 2), as well as HUVEC (lane 4), demonstrated a strong signal of expected size (432 bp) for CAR. The presence of GAPDH (627 bp) in all samples demonstrates equal representation of mRNA from each sample.