In contrast to present study of association of SFTPA1 and SFTPA2 with ARF, a previous study has shown that the majority of intergenic interactions associated with CF in a two-SNP model involved SNPs of SFTPB and SFTPC. Only two intergenic interactions were observed among the SFTPA1 and SFTPA2 SNPs [19]. Here, SFTPA2 is linked to cystic fibrosis.