Blocking HOX A5 expression increases the generation of BFU-E. Ex vivo expansion cultures of CD34⁺ cells with HOX A5 antisense, sense, or nonsense ODN were plated into colony assays containing IL-3, IL-6, SCF, and G-CSF and 2 U Epo (see Materials and Methods). Data are reported relative to the number of colonies generated from nonsense ODN-treated cells and are representative of the mean of three independent experiments, with each experiment containing three assay wells.