At the permissive temperature of 20°C, GSCs were maintained normally and LST-1V5 distribution appeared normal, but at restrictive temperature a germline tumor formed and LST-1V5 expanded to fill that tumor (Fig. 1C), but on a cell-by-cell basis LST-1 abundance in the tumors was comparable to regions of normal LST-1 expression in the distal gonad of non-tumorous strains. The gene discussed is LST1; the disease is neoplasm.