Recognizes a protein of 51 kDa, which is identified as FLI1. This protein, a member of the ETS family of DNA binding transcription factors, is involved in cellular proliferation and tumorigenesis. Ets-1 is the prototype member of a family of genes identified based on homology to the v-Ets oncogene isolated from the E26 erythroblastosis virus. Members of the Ets gene family share a highly conserved carboxy-terminal domain containing a sequence related to the SV40 large T antigen nuclear localization signal sequence.