IL17A and breast cancer: In addition, a decrease in the value of the Cxcl1-to-S100a8 ratio was observed in diseased lungs of Ifng−/− and Il17a/Il17f−/− transgenic C57 mice compared to the diseased lungs of mock C57 mice, indicating that Th1 and Th17 signals derived from the host immunity contributed to preventing lethal lung metastases in breast cancer.