NFKB1 and bronchopulmonary dysplasia: Other studies have also demonstrated the utility of TA analysis in investigating BPD, such as the finding that infants with a higher concentration of the transcription factor nuclear factor kappa B (NF-κB) in TA during the initial 3 days of life are more likely to develop BPD [12], and that higher levels of SPARC (Secreted Protein, Acidic, Rich in Cysteine) in the first week conferred a higher risk of BPD development or death [13].