[1] Leaman et al. showed that the miR-2 family regulates cell survival by translational repression of proapoptotic factors.

Mir-2 hairpin precursor sequences are highly conserved, in particular in their 3' arm in which the first 10 nucleotides are identical to all family members.

A notable exception has been observed in Drosophila melanogaster, in which the mir-2 family is organized in two clusters and two single loci.

Since most paralogous microRNAs conserve their function, it has been suggested that mir-2 evolution is dominated by a birth-and-death dynamics driven by random drift.

The functional diversification of microRNAs may require breaking the genomic linkage between paralogs, probably to avoid the co-regulation of multiple products by the same regulatory sequences.

[2] The repression of rpr and grim by the Hox gene ABD-B prevents apoptosis in neural cells.