*2.8. Statistical Analysis*

The miRNA expression levels from the array experiments were analyzed by SDS software version 2.2.2 (Applied Biosystems, foster city, CA, USA). The delat Ct values were calculated against U6 internal control. Heatmaps of differentially expressed miRNAs were analyzed by R software. Other data were analyzed using Student's *t*-test to determine statistical significance among the different groups. *p*-values (represented by asterisks), where \* *p* < 0.05; \*\* *p* < 0.01; \*\*\* *p* < 0.001; \*\*\*\* *p* < 0.0001.
