Quercetin and isoquercitrin, both flavonol compounds having A 331440 dihydrochloride similar structures, are widely distributed in nature. Quercetin has been shown to have an inhibitory effect on lipopolysaccharide- induced nitric oxide synthase gene expression and to inhibit NF-��B activation in human synovial cells, primary cultured rat proximal tubule cells, and rat aortic smooth muscle cells. Isoquercitrin, a glucose-bound derivative of quercetin, has also been shown to have anti-oxidant and anti-inflammation properties. Recently, these flavonol compounds have been reported to have anti-viral activity against viruses such as influenza, poliovirus, adenovirus, respiratory syncytial virus, SARS coronavirus, and HIV. HSV infection can induce oxygen stress, and the viral ICP27 protein can induce apoptotic cell death by increasing cellular reactive oxygen species. In this report, quercetin and 8-Cyclopentyl-1,3-dimethylxanthine isoquercitrin are shown to inhibit HSV-induced NF-��B activation. Further studies are needed to clarify the correlation between the anti-oxidant properties and the anti-HSV activities of quercetin and isoquercitrin. Quercetin is a small molecule, and our study showed that it could inhibit HSV binding to the cell surface. We hypothesize that this small molecular compound may compete for the gD binding site with a cellular receptor such as heparin sulfate or nectin-1. However, more work will be needed to test this hypothesis. Circulating tumor cell analysis may assist in the clinical management of melanoma. CTCs are cancer cells that have dissociated from the primary tumor and can be identified in peripheral blood through blood draws obtained with minimal risk. CTCs are rare, usually representing no more than one in one million peripheral blood cells, and potentially carry prognostic significance, as suggested in studies of breast, colorectal, and prostate cancers. Serial CTC counts before and after treatment may also help clarify disease status or risk of recurrence. Because melanoma is derived from neural crest cells and thus often exhibits mesenchymal features, conventional CTC detection platforms designed for epithelial cancers using cell surface markers may not be optimal for patients with melanoma. However, alternative cell surface markers, such as melanoma-specific cell surface proteoglycans, have aided the detection of CTCs in melanoma patients. Clinical studies utilizing reverse transcriptase polymerase chain reaction to identify melanoma-specific RNA products in the blood have suggested potential prognostic value, though the precise origin of these products are unknown and may represent primary tumor mRNA shedding rather than CTC-derived mRNA. Possible biological or technical hurdles with these CTC detection methods may include variability of cell surface marker expression or the uncertainty of the precise cellular origin of RT-PCR products, such as whether they are derived from live, dead, or dying cells.