HLA-C and viral infectious disease: Then, the combination of KIR2DL2 with the different HLA-C genotypes was also analyzed, and a statistically significant increase in the combination of KIR2DL2+/C1C1 was observed in AC patients with viral infection (Figure 2) compared with these patients without viral infection (45.9% vs. 24.5%, OR = 0.382; 95% CI: 0.175–0.837, p = 0.021).