The length distribution of small RNAs. Y-axis represents percentages of small RNA identified in the study. X-axis represents the length of small RNA. Six libraries are shown by different colors. The figure shows that 21 nt to 24 nt were highest frequency (nearly 90%) among all of the clean reads in each library, with 24 nt as the most abundant (close to 50%) small RNA length, followed by 23 nt, 21 nt, and 20 nt, in that order.