These commonly include parathyroid hormone (PTH)-related protein (PTHrp) secreted from tumour cells, known as humoural hypercalcaemia of malignancy, local osteolytic metastases or high-serum 1,25-dihydroxyvitamin D (calcitriol) causing increased calcium absorption and bone resorption (1). The gene discussed is PTHLH; the disease is neoplasm.