demonstrates specificity for prostate cells, decreased activity in non-prostate control cells, and improves upon earlier vector designs. GFP fluorescence of (a) LNCaP cells and (b) U251MG cells. LNCaP and U251MG cells were seeded at 1.25 × 104 cells/well of a 96-well plate and infected with Ad/GFPTET, Ad/GFPPS/TR, Ad/GFPPFLPS, Ad/GFPDiSTRES, or Ad/C.LacZ (negative control) in the presence of 30 nM DHT at MOI 1, 10, 100, or 1000. 2 days post-infection, cell lysates were assayed for GFP fluorescence. RFU: relative fluorescence units. MOI values were based on IU/ml.