Furthermore, we demonstrated that intradermal injection of mouse ears with live P. acnes induces tremendous infiltration of ASMase-expressed CD11b+ macrophages (Figure 4B and C), consistent with our previous observation that injection of live P. acnes into an implanted tissue chamber-imitated acne microenvironment recruited remarkable CD11b+ macrophages [33]. This evidence concerns the gene SMPD1 and acne.