Figure 3: Differences in miRNA expression in PTC patients with different clinicopathological features. miRNA-221, miRNA-222, miRNA-146b, and miRNA-181 expression levels were significantly higher in BRAF mutation group than in non-BRAF mutation group ( for all comparisons). miRNA-21 expression level was not significantly different between the two groups ( ) (a). The levels of miRNA-221 and miRNA-181 were significantly higher in patients with tumor diameter ≥2 cm than <2 cm ( and , resp.) (b). The overexpression of miRNA-221 and miRNA-222 was found in patients with advanced TNM stage ( and , resp.) (c) and lymph node metastasis ( and , resp.) (d). Statistically significant differences were determined by the Mann-Whitney test.