The chemotactic effect of the supernatants from mock- and PCV2-inoculated monocyte-derived macrophages (MDM) collected at 24 h post-inoculation (HPI) on blood monocytes (Mo) as determined by a migration assay using Transwell^® plates. Data are expressed as (A) the total number of Mo attributed to the lower chambers shown as mean ± SD of three pigs of the Transwell^® plate and (B) dot plot of each of the three pigs used in the experiment by showing the total number of Mo attracted to the lower chamber of the Transwell^® plate. (A) □: medium control, ■: mock-inoculated, : PCV2-inoculated; (B) ●: medium control, ▽: mock-inoculated, ■: PCV2-inoculated.