Serological reactivity of the recombinant DPPA2 protein in a subset of ovarian cancer patients. The presence of anti-DPPA2 antibodies in serum samples was assessed by ELISA. Serum obtained from a seropositive NY-ESO-1 patient (SRM13) was used as a positive control and that obtained from a seronegative NY-ESO-1 patient (SRM24) was used as a negative control. Sera #15559, #15555, and #15418 tested negative for DPPA2 expression by RT-PCR.