Explain this to me in simplest terms : Frozen tissues were homogenized using automated cell homogenizer for extraction of RNA. RNA was extracted using a total RNA preparation kit from Qiagen Biotechnology Company. RNA quantity and quality (i.e. percentage of fragments longer than 200 bp) were determined using Agilent Bioanalyzer. Only high- quality RNA (distribution value 200 or higher) was used for the tran- scriptome profilin