Of the five patients who developed PPGL-related metastasis (tumor size at adrenalectomy: 5.5, 9.5, 10.5, 10.8, and 12 cm, respectively), two (40%) had a KI67 >2% (3% and 12%, respectively) at surgery, while the other three patients (60%) had a KI67 ≤1%. This evidence concerns the gene MKI67 and neoplasm.