miR-31 expression is significantly upregulated in the colon (A) and ileum (B) of treatment-naive pediatric CD samples (colon, n = 76; ileum, n = 60) compared with pediatric NIBD samples (colon, n = 48; ileum, n = 50). Principal components analysis of miRNA expression profiles from small RNA-seq results in distinct clusters of NIBD and CD patients for colon (C) and ileum (D) samples. Points are colored according to miR-31 expression (blue–gold, low–high). Significance determined by a 2-tailed unpaired Student’s t test where P < 0.05. Data presented as mean ± SEM.