Carcinogenesis was investigated in Ptx3−/− and Ptx3+/+ mice treated with 3-methylcholantrene (3-MCA) or 7,12-dimethylbenz [α] anthracene/terephthalic acid (DMBA/TPA) to induce formation of sarcomas or papillomas/skin carcinomas, respectively. The gene discussed is PTX3; the disease is sarcoma.