SFTPB and chronic obstructive pulmonary disease: Of note, this first intronic region contains a SNP (rs3024791) that is associated with chronic obstructive pulmonary disease (COPD)39, suggesting that this region is a critical region regulated by NKX2-1 that influences disease severity by affecting the expression of SFTPB. In addition to this region located at the first intron, using the ChIP-seq with CRISPRi approach, we identified another functionally important NKX2-1-binding site in the upstream region (Fig. 2).