We successfully employed the DEP operating parameters established for the ASPS-1 cell line in the cross-validation studies to isolate CTCs from blood samples of all 6 patients with metastatic ASPS, and confirmed their tumor origin using TFE3 break-apart FISH for the detection of the chromosomal translocation of ASPL and TFE3 genes [10]. The gene discussed is TFE3; the disease is neoplasm.