They used real-time PCR to analyze the downregulation of four genes, HYAL1, HYAL2, RASSF1A, and NPRL2, in lung cancer and found that they were downregulated in non-small cell lung cancer, the first stage of squamous cell lung cancer, and were significantly associated with lung adenocarcinoma progression. Here, HYAL2 is linked to lung adenocarcinoma.