MIER2 functions as a transcriptional repressor. According to the NCBI Gene summary, it enables histone deacetylase binding activity and contributes to histone deacetylase activity, and it is predicted to take part in the negative regulation of transcription by RNA polymerase II. Histone deacetylases remove acetyl groups from histones, a modification associated with a more repressive chromatin state, so a protein that binds these enzymes is well placed to bring repression to target genes.

The MIER2 protein is part of a protein-containing complex. UniProt lists its subcellular location as the nucleus, while the NCBI Gene summary reports it in both the cytoplasm and the nucleus. HGNC places the gene in two groups: Myb/SANT domain containing, and MIER complex subunits. The human MIER2 gene lies on chromosome 19 at 19p13.3, and a mouse ortholog, Mier2, is recorded.

The name reflects the family's origin. The approved name, MIER family member 2, replaces the earlier designations KIAA1193 and mesoderm induction early response 1, family member 2. UniProt uses the name mesoderm induction early response protein 2. Researchers studying chromatin regulation, histone deacetylase-containing complexes and transcriptional repression use MIER2 as a subunit of the MIER complex.