Pancreatic stellate cells that express CD10 are associated with more aggressive pancreatic carcinomas and increased metalloproteinease 3 enzyme production, which is involved in basement membrane degradation and, therefore, tumor invasiveness.9 Interestingly, the sarcomatous component of the pancreatic carcinosarcoma from this case was strongly and diffusely positive for CD10. The gene discussed is MME; the disease is neoplasm.