SFTPA2 and asthma: Since our clinical data showed an association between the SP-A2 SNP, asthma status and lung function, we further tested the ability of two SP-A recombinant genetic variants (full-length containing either 223Q or 223K) to suppress inflammation to IL-13 ex vivo. We used an affinity purification procedure, which requires the C-type lectin activity of the protein be functional, thus ensuring that we are purifying properly folded and active forms of SP-A.