CEBPB and infection: However, in A549 cells, we found that binding of CEBPB to motif 1 and motif 2 in site 1 may have an inhibitory effect on DEFB1 transcription, as truncation of motif 1, motif 2, or motif 1+2 (site 1 as a whole) increased DEFB1 transcription after H37Rv infection.