One of the available methods for the improved detection of micrometastases in regional LNs can be, based on data provided by recent studies, both the proof of tumor cells by immunohistochemical examination with an antibody against cytokeratin 19 (IHC CK19), and the molecular genetic method OSNA (One-Step Nucleic Acid Amplification), which detects CK19 mRNA [2,3,4]. The gene discussed is KRT19; the disease is neoplasm.