CXCL9 and abscess: To evaluate cellular sources of CXCL9/10 in bone marrow myeloid cells during S. aureus infection, we isolated monocytes, bone marrow-derived macrophages (BMDMs) and neutrophils, which are main components of S. aureus abscess [28], from the femoral bone marrow in 8-week-old mice and 10-month-old mice, and challenged them with various MOI of S. aureus.