Transcription factor. Directly controls the expression of cytokine and chemokine genes in a wide variety of different cellular contexts. May control the differentiation, survival and proliferation of lymphoid cells. May also regulate angiogenesis through regulation of expression of genes controlling endothelial cell migration and invasion. Binds DNA as a homodimer; homodimerization is required for transcription activation. Interacts with MAF and MAFB. Interacts with PAX5; the interaction alters DNA-binding properties (By similarity). Interacts with DAXX. Interacts with UBE2I. Interacts with SP100; the interaction is direct and modulates ETS1 transcriptional activity. Delocalizes from nucleus to cytoplasm when coexpressed with isoform Ets-1 p27. Highly expressed within lymphoid cells. Isoforms c-ETS-1A and Ets-1 p27 are both detected in all fetal tissues tested, but vary with tissue type in adult tissues. None is detected in brain or kidney. Up-regulated by retinoic acid, VEGF, TNF-alpha/TNFA, lipopolysaccharide and in response to hypoxia (at protein level). Sumoylated on Lys-15 and Lys-227, preferentially with SUMO2; which inhibits transcriptional activity. Ubiquitinated; which induces proteasomal degradation. Acts as a dominant-negative for isoform c-ETS-1A. Belongs to the ETS family.