Intact-PTH levels showed a step up in the territory of the central left branchiocephalic vein compared with both right and left subclavian vein and right atrium (branchiocephalic vein, 1205 pg/mL; right subclavian vein, 256 pg/mL; left subclavian vein, 259 pg/mL; right atrium, 252 pg/mL), corresponding to the anatomic localization of the cyst-like tumor in the previous imaging studies. The gene discussed is PTH; the disease is cyst.