In a retrospective study of circulating levels of PTHrP within 1149 hypercalcaemic lung cancer patients, levels of circulating PTHrP > 150 pmol/L were found to be associated with decreased median survival (1.4 months vs. 5.4 months) and bone metastasis incidence (12.5% vs. 71.4%) [129]. This evidence concerns the gene PTHLH and bone metastasis.