Interferons are known to modulate several cellular functions by the induction of different proteins. In our study interferon-gamma and -alpha augmented presentation of one specific ovarian cancer antigen recognized by the antibody OV632 on the cell surface on one of four ovarian carcinoma cell lines in vitro (HTB-77). The interferon-gamma effect reached a maximum after 24 of treatment. Both HLA-DR and OV632 antigen expression were increased by interferon-gamma on HTB-77 cells whereas the two cell lines OVCAR-3 and 2780, which respond to an interferon-gamma treatment with a reduced proliferation and induction of HLA-DR, and also the interferon-resistant CRL-1572 were found to be resistant regarding OV632 epitope modulation. The demonstration of OV632 expression provides an important insight into the potential regulatory mechanism governing this tumor marker.