CCL4 and infection: When endotoxin free [<0.06 endotoxin units (EU)/ml, which is the EU standard for water for injection] PAMAM-DG was added to primary human monocytes before adding E. coli at a multiplicity of infection of 5, there was a 1923-fold reduction in interleukin (IL)-6 messenger RNA (mRNA) expression with a mean reduction of 103 ± 32-fold in IL-8 (CXCL-8), tumour-necrosis factor (TNF)-α, IL-1β, chemokine (C-C motif) ligand 3 (CCL3) (MIP-1α) and chemokine (C-C motif) ligand 4 (CCL4) (MIP-1β) mRNA expression (Fig 1A).