FN1 and breast cancer: In addition, when CXCL9 combined with fibronectin 1 (Fibronectin 1 > 200 pg/mL as positive; 150 < fibronectin 1 < 200 pg/mL and CXCL9 concentrations >1000 pg/mL as positive), the sensitivity for BC diagnosis was 53% and specificity was 97%.