Component of the transcription complexes of the pulmonary surfactant-associated protein-B (SFTPB) and -C (SFTPC). Enhances homeobox protein Nkx-2.1-activated SFTPB and SFTPC promoter activities. . This is the function of CCDC59 (coiled-coil domain containing 59, Ensembl gene identifier ENSG00000133773).