Our previous work showed that O3 exposure induced the expression of SP-D in the BAL >48 h later, as a protective mechanism (28, 33, 39) but O3-induced airway inflammation in allergen challenged mice also led to appearance of abnormal oligomeric molecular forms of SP-D indicating that oxidative stress can cause conformational changes that can inactivate SP-D's immunoprotective function (28, 32, 33). The gene discussed is SFTPD; the disease is inflammation.