The microRNA array was performed by Kangcheng Bio-Tech, Inc. Total RNA was isolated from peripheral blood of patients with DN and controls using a miRNeasy kit (Qiagen, Inc.). The RNA purity was determined via NanoDrop ND-1000 spectrophotometry (Thermo Fisher Scientific, Inc.) and the RNA quality was determined using 1% agarose-formaldehyde denaturing gel electrophoresis. After RNA quantitation, the samples were assessed using the miRCURY LNA™ Array v. 16.0 (Exiqon A/S; Qiagen, Inc.) according to the manufacturer's protocol. The procedure and imaging processes were performed as described previously (16 (link)). The microarray data were analyzed using Agilent Feature Extraction software (version 10.7; Agilent Technologies, Inc.) (17 (link)). Differentially expressed miRNAs were screened with an unpaired t-test (P<0.05) combined with a significant threshold value of a fold change [FC; (log2 (FC) >2 for upregulated, and log2 (FC) ≤-2 for downregulated]. The microarray data that support the findings of this study are available from the corresponding author upon reasonable request.