MUC1 and non-small cell lung carcinoma: PPARγ activation by ciglitazone and 15d-PGJ2 in multiple NSCLC cell lines enhances expression of gelsolin, Mad, and p21, considered general differentiation markers, while reducing expression of lung lineage-specific markers associated with lung progenitor cells such as mucin 1 (MUC1) and surfactant protein-A (SP-A) [25].