CXCL10 and BK-virus nephropathy: The CXCL10 urine concentration further increased from low‐level BKPyV DNAemia when viral DNA loads exceeded 1000 copies/ml but no clinical manifestations of PVAN were observed yet (median increase: 87.59 pg/ml, 95% CI: 39.02–148.07, P = 0.0005).