TFF2 and cystic fibrosis: SFTPA2 SNP rs1059046 appears to stand out from the other SFTPA2 SNPs studied, as this SNP (1) is associated with CF via five of the total nine interactions observed with the other SP genes, (2) is the only SNP that shows interactions with two SFTPA1 SNPs, and (3) shows interactions with both hydrophobic surfactant proteins SFTPB and SFTPC (Figure 1A).