The majority of PCI-6A cells, which had been generated from a primary tumour, were highly PRLR positive, whereas all PCI-6B cells generated from a metachronously developed corresponding lymph node metastasis were negative for PRLR, both on the cell surface and in the cytoplasm (Figure 1B). The gene discussed is PRLR; the disease is metastatic malignant neoplasm in the lymph nodes.