An example of isomiR expression and interaction with circRNA. (a-b) Hsa-mir-204 has two mature products, but miR-204-5p is the dominant miRNA generated. From each miRNA locus, multiple isomiR can be detected with various expression patterns and sequences. However, some of these isomiRs are more dominant and others are rare. (c) Sequence distribution patterns and interactions with circRNA. Multiple isomiRs may interact with the same circRNA, as long as the sequence in the binding region is homologous.