If CCND1 amplification was present in the primary tumours, CDKN2A homozygous deletion appeared in the bone metastases (HBCx-131) or in the PDX (HBCx-134), in patients who recurred 10 years and 1 year, respectively, after treatment with an aromatase inhibitor. The gene discussed is CDKN2A; the disease is neoplasm.