Transcription factor (By similarity). Involved in modulating innate immune response pathways, acting to promote resistance against infection by Gram-negative bacterium P.aeruginosa strain PA14 (PubMed:34804026). May act as part of a feedback regulatory loop with the pmk-1/p38 MAPK pathway (PubMed:34804026). May also function in concert with CCAAT/enhancer-binding protein cebp-2 to mediate immune responses, independently of the pmk-1/p38 MAPK pathway (PubMed:34804026). Interacts with CCAAT/enhancer-binding protein cebp-2. Expressed in intestine, pharynx, and hypodermis at larval stage L4. By exposure to the Gram-negative bacterium P.aeruginosa strain PA14. RNAi-mediated knockdown targeted to the intestine, but not to neurons, hypodermis, muscle or germline, reduced the resistance to infection by the Gram-positive bacterium P.aeruginosa strain PA14 (PubMed:34804026). Reduces expression of pmk-1 pathway dependent genes, such as systemic stress signaling mediator sysm-1 and infection response gene irg-4 (PubMed:34804026). Belongs to the bZIP family.