In the present report, we analyzed FAK expression in 196 stage II-IV breast cancer patients and 117 metastatic samples available matched to the primary tumors using the tissue microarray (TMA) technique which allowed us to analyze hundreds of tissue samples simultaneously using one paraffin block, reducing variability between samples in the case of regular immunohistochemical staining of many samples of large tumor sections [13]. This evidence concerns the gene PTK2 and breast cancer.