However, we included patients with both non-progressive and progressive CPP according to the classification reported by De Filippo et al. In that study, the combination of a serum inhibin B concentration of 20 pg/mL and a basal LH level of ≤0.2 IU/L results in 98% sensitivity and specificity to differentiate the non-progressive form from the progressive form. The gene discussed is PLOD1; the disease is central precocious puberty.