Metastases to bone alter physiological bone remodelling: advanced breast and lung cancers predominantly cause osteolytic lesions (excessive bone degradation),75,76 while prostate cancer typically induces osteosclerotic lesions (excessive bone formation).77 BSP expression in skeletal metastases may modulate both tumour growth and pathological bone remodelling, as explored in this review. Here, IBSP is linked to lung cancer.