PAX 5 expression was evaluated in small cell lung cancer and other cancers; determined that PAX5 could regulate the transcription of c-Met; PAX5 protein expression was relatively strong in small-cell lung cancer; expression was not detected in non-SCLC

lung cancer: PAX5 was frequently expressed in atypical carcinoids, SCLCs, and large cell neuroendocrine carcinomas but tended to be negative in typical carcinoids. Frequently co-expressed with c-Met.

PAX2 and PAX5 are useful biomarker in the differential diagnosis of lung cancer

PAX5 was found to be an epigenetically inactivated tumor suppressor that inhibited non-small-cell lung proliferation and metastasis, through down-regulating the beta-catenin pathway and up-regulating GADD45G expression.