CCL4 and pneumococcal infection: γδ TCR deficient mice show decreased neutrophil accumulation in small intestine and lungs triggered by thermal injury or Streptococcus pneumoniae infection, due to the impairment of CCL4/MIP-1β, CXCL1 (keratinocyte derived chemokine, KC), and CXCL2/MIP-2 (Toth et al., 2004; Nakasone et al., 2007).