Elevated serum BSP levels are associated with tumour grade, cancer stage and secondary cancer developments, such as skeletal metastases, in patients with multiple myeloma,84 lung,85 and prostate cancers.86,87 However, one study reported that TNM staging, which incorporates tumour size, lymph node status and metastasis, did not significantly influence serum BSP levels in pancreatic adenocarcinoma patients,88 suggesting that serum BSP may not universally correlate with clinicopathological features across all cancer types. This evidence concerns the gene IBSP and Familial prostate cancer.