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) applications in using blood stem cells for tissue repair, transplantation and other therapeutic applications. This gene can be classified as a proto-oncogene. During chromosomal translocations that occur in cell division, "ERG" can accidentally get stuck onto a different chromosome than where it belongs. This is analogous to another translocation, the Philadelphia chromosome. This results in fusion gene products, which can have bad consequences for cells. Examples of these fusion gene products would be TMPRSS2-ERG and NDRG1-ERG in prostate cancer, EWS-ERG in Ewing’s sarcoma, and FUS-ERG in acute myeloid leukemia. DNA binding protein ERG fuses with RNA binding proteins EWS and