The HSPD1′s involvement in S. suis-serovar-2-induced apoptosis has been described in our previous study [14], which proved that Eno binds to 40S ribosomal protein SA (RPSA) and migrates from the surface of PBMECs to the cytoplasm during infection, and finally leads to HSPD1-increased expression and apoptosis. Here, RPSA is linked to infection.