DNMT3B and susceptibility to pneumonia measurement: Given the reported data, many spliced variants of DNMT3B are expressed in a tissue, cell, and/or developmental stage-specific manner [6,9], in this study, we focus on the expression pattern of DNMT3B in porcine alveolar macrophages (PAM), which are not only the major immune cells in pig lungs, but also the important resources of the inflammatory cytokines in pneumonia of pigs [10,11].