CXCL16 and vasculitis: qRT-PCR validated the microarray analysis indicating that CXCL16 gene expression is up-regulated in HCV MC vasculitis patients [1.90 ± 0.60 (NV), 4.60 ± 0.80 (HCV MC-Vasc), 2.50 ± 0.60 (HCV), 3.10 ± 0.50 (HIV/HCV); p = 0.02 between HCV MC-Vasc and HCV viremic].