CCDC59 (coiled-coil domain containing 59) is a transcriptional coactivator that enhances expression of pulmonary surfactant proteins SP-B and SP-C by potentiating thyroid transcription factor-1 (TTF-1) activity 1. The protein functions as a component of transcription complexes regulating SFTPB and SFTPC promoters, binding to protein and RNA molecules within the nucleus 1. In pulmonary pathology, CCDC59 overexpression in type II alveolar epithelial cells significantly alleviates bleomycin-induced inflammation and fibrosis in mice by upregulating SP-B and SP-C expression, improving lung function and protecting against pulmonary inflammatory responses 1. Additionally, CCDC59 alleviates HIPPO pathway hyperactivation and increases proliferative capacity of alveolar epithelial cells, suggesting therapeutic potential for pulmonary fibrosis 1. Beyond lung disease, CCDC59 is overexpressed in multiple cancers, particularly liver hepatocellular carcinoma and bladder cancer, where it correlates with poor prognosis and tumor mutational burden 2. In hepatocellular carcinoma cells, CCDC59 knockdown inhibits proliferation, migration, invasion, and cell cycle progression, identifying it as a potential therapeutic target 2. CCDC59 was also identified as a key diagnostic biomarker in osteoarthritis 3, suggesting broader pathophysiological roles beyond its characterized surfactant protein regulatory function.