PPBP and infection: As shown by Xiu et al. [56] other cytokines (e.g. Il-8; IL-1-alpha), including chemokines (chemokine ligand 5 – CXCL5; chemokine ligand 5 – C-C motif; chemokine receptor 7 – CXCL7) were upregulated after infection caused by S. aureus.