In this study, when analysed in a multivariate model, the absence of expression of PTHrP in the primary tumour was an independent predictor of BM (p = 0.002), together with the number of positive axillary LN (p<0.001), lymphatic/vascular invasion (p = 0.002), and the absence of PR staining (p = 0.04). The gene discussed is PTHLH; the disease is neoplasm.