While each drug is capable of building new bone, they remain (i) expensive; (ii) require subcutaneous injection (PTH/rP-daily; EVENITY-monthly); (iii) have limited efficacy (PTH/rP ∼18-months; EVENITY 12-doses, switching to standard anti-resorptives thereafter); (iv) carry increased treatment risks (PTH/rP-osteosarcoma; EVENITY-cardiovascular) and thus; (v) are restricted to patients with the most severe osteoporosis. The gene discussed is PTH; the disease is osteosarcoma.