Putative binding sites detected in the 137-bp upstream of the transcription start site of the WASP gene. Solid arrows, Ets-1; dashed arrows, c-Rel and PU.1. The PU.1 consensus was found by comparing the WASP enhancer region with the list of binding sites for vertebrate transcription factors published by Faisst and Meyer³⁵; the Ets-1 and c-Rel consensus were identified by using the TFsearch database (http://www.genome.ad.jp/SIT/TFSEARCH.html). Gray lines indicate the EtsP and EtsD oligonucleotides used in the EMSA assays shown in Fig4.