Matched lung parenchyma tissuesamples included 25 squamous cell carcinomas and 31 adenocarcinomas.Immunohistochemistry was performed to analyze for the distribution of hyaluronidase(Hyal)-1 and −3, and hyaluronan synthases (HAS)-1, −2, and −3. The gene discussed is HAS1; the disease is adenocarcinoma.