CXCL1 and breast cancer: As expected, the Cxcl1-to-S100a8 ratio had a significantly higher value in grade 1 and 2 breast cancers than in grade 3 cancers (Fig. 8c, grade 3 cancers are more aggressive than grade 1 and grade 2 cancers), like our observation in animal models that this ratio had a higher value in non-metastatic 67NR and 4T07 cancers than metastatic 4T1 cancer.