S100A4 mediates breast cancer metastasis, and its expression is controlled via the β‐catenin pathway (Bresnick et al., 2015); therefore, high levels of KLK6 could activate the β‐catenin pathway as reported in keratinocytes (Klucky et al., 2007), to drive the expression of S100A4. This evidence concerns the gene S100A4 and breast carcinoma.