ITGAX and Mycobacterium infection: Compared to sham room air exposure or cigarette smoking cessation groups, continuous cigarette smoke exposure dramatically reduced the frequency and total numbers of CD11b+CD11c−, CD11b+CD11c+, and CD11b−CD11c+ APCs, indicating a global reduction in the number of APCs in the lungs of these animals following mycobacterial infection (Figure 7A).