For further selection of scFv-Fc candidates, specificity thresholds were defined for on-target binding (>50% of Jurkat FOLR1 KI cells), off-target binding (<10% of on OV-90 FOLR1 KO cells), and on-tumor binding (>50% on-target binding on ovarian cancer tissue). The gene discussed is FOLR1; the disease is ovarian cancer.