Western blot analysis of urine from a patient with NY-ESO-1+ thyroid cancer (NW1231). The urine, diluted 1:1, 1:100, and 1:1,000, was used to probe a blot with the lysate of 5x10⁶ COS-7 cells transfected with NY-ESO-1 and thus containing naturally produced NY-ESO-1 protein (22 kDa). NY-ESO-1 urine antibody was detected at urine dilutions of 1:1 and 1:100. Urine from a healthy donor (HD) at a dilution of 1:1 served as a negative control. All samples tested show non-specific reactivity with a COS-7 cell component (16 kDa).