
PDGF-BB expression in serum samples of SFTS patients and controls {#s4_5}
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To compare the expression patterns of PDGF-BB, acute SFTS patients and age matched controls were selected to measure the PDGF-BB levels by using PDGF-BB ELISA assay (GenWay Biotech, USA). The SFTS patients who were successfully followed up and sampled during the convalescence were also tested for the PDGF-BB evaluation. All measurements were performed in duplicate.

Statistical analysis {#s4_6}
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Genotype and allele frequencies for polymorphisms were determined by gene counting. The fitness to the Hardy-Weinberg equilibrium was tested using the *χ*^2^ test. Associations between polymorphisms and risk of SFTS were estimated by use of logistic regression analyses. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to measure the strength of association. In view of the multiple comparisons, the correction factor n (m--1) (n loci with m alleles each) was applied to correct the significance level. The PDGF-BB concentrations were log transformed, and tested for differences between different groups by two-sample Wilcoxon rank-sum test. These analyses were performed using SPSS software (version 17.0, SPSS Inc., Chicago, IL).

SUPPLEMENTARY FIGURE AND TABLES {#s5}
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We thank all the tested individuals, their families, and collaborating clinicians for their participation.

**CONFLICTS OF INTEREST**

The authors declare that they have no conflict of interest.

**FINANCIAL SUPPORT**

This work was supported in part by grants from the National Natural Science Foundation (No. 81222037, 81473023), China Mega-Project on Infectious Disease Prevention (No. 2013ZX10004202) and the Special Fund for Quarantine-Scientific Research in the Public Interest (201310076).


Introduction {#Sec1}
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One of the remarkable features of the Integer Quantum Hall Effect (QHE) is the impressive precision of the quantization of the plate