To identify the effect of miR-146a in various joint cell populations during the early phase of infection ex vivo, we digested joints with purified collagenase to release cells into a single-cell solution in order to identify and isolate cell fractions based on lineage markers, including CD45 for leukocytes, CD11b for myeloid cells, CD31 for endothelial cells, and CD29 for fibroblast-enriched cells (Figure 5A). Here, PECAM1 is linked to infection.