Source:http://linkedlifedata.com/resource/umls/id/C0021021
MSH: A site located in the INTRONS at the 5' end of each constant region segment of a immunoglobulin heavy-chain gene where recombination (or rearrangement) occur during IMMUNOGLOBULIN CLASS SWITCHING. Ig switch regions are found on genes encoding all five classes (IMMUNOGLOBULIN ISOTYPES) of IMMUNOGLOBULIN HEAVY CHAINS.,NCI: A site on a segment of a B-cell immunoglobulin heavy-chain gene where recombination (or rearrangement) can occur. It is involved in isotype or allotype switching and maturation of the immune response. Ig switch regions are found on genes encoding all five immunoglobulin heavy chains.