Using cut-off values determined by ROC curve analysis, plasma CCN2 ≥ 86 μg/L, age ≥ 67 years, presence of ≥ 9 liver metastases and duration of illness ≥ 46 months were significantly associated with at least mild or greater TR/PR, as was presence of the carcinoid syndrome. The gene discussed is CCN2; the disease is carcinoid syndrome.