In the Japanese population, Nagao et al. identified single-nucleotide polymorphisms in the HLA-DR/DQ, in NRP2 and IGFBP4 loci, which increase and reduce the risk of LP, respectively, and those authors propose that these genetic variants might be used to identify patients with HCV infection who are at risk for lichen planus [220]. The gene discussed is IGFBP4; the disease is lichen planus.