In our signature, F2R (PAR1) overexpression relative to KLF4 is predictive for RD, consistent with current evidence linking F2R overexpression to BC invasiveness and metastasis, especially in ER-negative tumors [47–50], while KLF4 overexpression is a favorable prognostic factor, especially in patients with TNBC [51–53]. This evidence concerns the gene KLF4 and breast cancer.