Due to these diagnostic ambiguities, this matched-pair analysis study was carried out with the objective of (1) assessing the role of patient characteristics to the change of serum CRP and WBC values when planning reimplantation in two-stage revision arthroplasty, and (2) investigating the diagnostic practicality of using the change, or delta (Δ), of these serum markers from preexplantation to prereimplantation as an indicator of infection eradication and optimal timing for reimplantation. The gene discussed is CRP; the disease is infection.