We therefore tested three different expression cassettes consisting of 17, 21, or 25 GGAA-repeats cloned directly upstream of YB-TATA in a dual luciferase reporter assay in 6 EwS cell lines (including TC-106, a cell line harboring the less common EWSR1-ERG fusion oncogene, which is structurally and functionally similar to EF1) and 7 control cell lines, comprising 7 different non-EwS cancer entities or tissue types [1, 16]. The gene discussed is ERG; the disease is cancer.