Grand Erg Oriental follow the wind's direction. There are other types of dunes, as well as "complex" dunes. Saharan winds are also known to clear an area of sand altogether, leaving bare rock (hamada) or gravel (reg). The "Grand Erg Oriental" is accessible overland by an Algerian road, which goes south from Constantine. It passes through the Aurès mountains, then salt lakes by the city of Biskra. Next the road skirts the western edge of the erg. After about 500 km. in all, it reaches the ancient oasis of Ourgla [Wargla]. Since late antiquity Wargla was a stop for the Saharan trade, being
ERG (gene) ERG (gene) ERG (ETS-related gene) is an oncogene. ERG is a member of the ETS (erythroblast transformation-specific) family of transcription factors. The "ERG" gene encodes for a protein, also called ERG, that functions as a transcriptional regulator. Genes in the ETS family regulate embryonic development, cell proliferation, differentiation, angiogenesis, inflammation, and apoptosis. Transcriptional regulator ERG is a nuclear protein that binds purine-rich sequences of DNA. Transcriptional regulator ERG is required for platelet adhesion to the subendothelium and regulates hematopoiesis. It has a DNA binding domain and a PNT (pointed) domain. ERG is expressed at higher levels in early myelocytes than