Moreover, despite their beneficial effects on bone mass, PTH and PTH-related protein (PTHrP) have been described to affect muscle size through the common PTH receptor (PTHR)28–30, therefore raising concerns that the administration of PTH peptide in patients with cancer or treated with chemotherapy, that are already at risk of significant muscle loss, may instead exacerbate their cachectic condition. The gene discussed is PTHLH; the disease is cancer.