KRT19 and breast cancer: To overcome this limit, Sysmex Corporation (Kobe, Japan) has developed an innovative molecular method, the One Step Nucleic Acid Amplification (OSNA) reaction, that in combination with the reagent “Lynoamp BC”, allows the rapid and accurate detection of cytokeratin 19 (CK19) mRNA in metastatic lymph nodes of breast, gastric and colon cancer patients [14–16].