SFTPA2 and asthma: We chose this particular region of the CRD based on our findings in asthma patients as described above and based on our studies in which full-length SP-A that contains the Q at position 223 was able to induce eosinophil apoptosis, which was CRD-dependent, while SP-A containing K at position 223 was not active in this function, as we reported previously (22).