CRP and white cell count; (2) preoperative aspiration including a-Defensin, cell count with polymorph cells, CRP aspiration, Leucocyte Esterase test and microbiology/culture from the aspirate and (3) perioperative microbiological swabs/probes and sonication of the removed implants should follow to diagnose PJI. The gene discussed is CRP; the disease is juvenile polyposis syndrome.