On the other hand, about 60% of melanoma metastases from lymph nodes or the liver overexpress POSTN. Analysis of newly-established melanoma cell lines and matched metastases revealed that, although stromal cells -presumably fibroblasts- are mostly responsible for periostin production in melanoma metastases, melanoma cells sometimes acquire the ability to express POSTN at high level. The gene discussed is POSTN; the disease is melanoma.