Antibody responses to recombinant OGFr and OGFr-ARF in melanoma patients. Synthetic peptides (0.5 µg/well) or recombinant OGFr (0.3 µg/well) were bound to ELISA plate wells and incubated with sera (diluted 1:1000) from 45 melanoma patients enrolled in the GM-CSF vaccine trial (A) or from 21 normal donors (B). Using a criterion of four standard deviations above the mean of the values observed in the normal donors (indicated by bars, panel A), the number of positive responses in the melanoma patients were as follows: OGFr 2/45, OGFr-ARF 5/45, MUC1 1/45 and recombinant OGFr 11/45.