Immunoreactivity of human monoclonal antibodies (hMAbs) 27.B1 and 27.F7 against different cancer cell lines. A, cELISA: The binding index is the normalized antibody binding relative to the background antibody reactivity with primary human fibroblasts. Both hMAbs 27.B1 and 27.F7 display an increased binding to formalin-fixed breast (MCF7) and ovarian (SKOV3) cancer cell lines in comparison to normal fibroblasts (WS1). B, and C, Western blot analysis: The target antigen, GIPC1, for monoclonal 27.B1 (B) and 27.F7 (C) in MCF7 and SKOV3 cancer cell lines was identified by Western blot. The target antigen is present in MCF7 (breast) and SKOV3 (ovarian) cell lines but is not detected in WS1 (normal fibroblasts). β-Actin served as the loading control.