Probable transcription activator for a number of lung-specific genes (PubMed:9676429). Mediates up-regulation of the E3 ligase IRF2BPL and drives ubiquitination and degradation of CTNNB1 (By similarity). Interacts with the transcription factors TBP and TFIIB. Uniquely expressed in the bronchiolar epithelium and in type II pneumocytes. Two activation domains, AD1 and AD2, C-terminal of (and distinct from) the forkhead domains are necessary for transcriptional activation.