Erg (landform) and western Asia, and Central Australia. In South America, ergs are limited by the Andes Mountains, but they do contain extremely large dunes in coastal Peru and northwestern Argentina. They are also found in several parts of the northeast coast of Brazil. The only active erg in North America is in the Gran Desierto de Altar () that extends from the Sonoran Desert in the northwestern Mexican state of Sonora to the Yuma Desert of Arizona and the Algodones Dunes of southeastern California. An erg that has been fixed by vegetation forms the Nebraska Sandhills (). Sand seas and dune
ERG (gene) TLS/FUS in Ewing's sarcoma and acute myeloid leukemias respectively and function as transcriptional activators. ERG and its fusion proteins EWS-ERG and TLS/FUS-ERG inhibit apoptosis. "ERG" can fuse with TMPRSS2 protein to form an oncogenic fusion gene that is commonly found in human prostate cancer, especially in hormone-refractory prostate cancer. This suggests that "ERG" overexpression may contribute to development of androgen-independence in prostate cancer through disruption of androgen receptor signaling. The fusion gene is critical to the progression of cancer because it inhibits the androgen receptor expression and it binds and inhibits androgen receptors already present in the cell. Essentially TMPRSS2-ERG