Using a gamma-counter, the binding to different cancer cell lines was investigated, evidencing that SKOV-3 cells, which are characterized by the highest HER2 receptor expression, displayed the highest affinity; the authors confirmed that the binding was dependent on DARPin G3-HER2 interaction by saturating SKOV-3 cells with trastuzumab, an anti-HER2 antibody. The gene discussed is ERBB2; the disease is cancer.