Except for lymph node status (28.6% of lymph node-negative tumours express high levels of PKD1 mRNA as compared to 55.6% of the lymph node-positive tumours, P = 0.034), no relationship was found between the expression pattern of PKD1 mRNA and most classical pathological and clinical parameters (age, SBR histological grade, macroscopic tumour size, PR and ERBB2 statuses and PIK3CA mutation status; Table 3). The gene discussed is PKD1; the disease is neoplasm.