However, the investigators participating in the UCLA study [21] and the ARNOS study, which was undertaken in France, suggested that low or very low PTH levels (< 50 pg/mL) may correlate with poor survival in HD patients.[22] In addition, the Cox regression analysis showed that higher ALP or lower iPTH levels were associated with higher levels of mortality in HD patients. The gene discussed is PTH; the disease is Huntington disease.