CCR5 and osteonecrosis: The CCL26 has a bactericidal activity verified against pathogens Streptococcus pneumoniae, Staphylococcus aureus, Nontypeable Haemophilus influenzae, and Pseudomonas aeruginosa63, while CCR5 has already been identified as biomarker for osteonecrosis of the femoral head in human plasma64.