Abstract In metazoans, gene duplication has given rise to paralogous transcription factors, which have functionally diversified to control cellular differentiation. While the majority of paralogous TFs are dispersed across different chromosomes, some remain clustered raising the question of whether genomic proximity confers any evolutionary advantage for TF clusters. To address this, we investigated a ~1 Mbp locus containing two ETS family paralogs, Ets1 and Fli1.