Membrane-spanning 4A genes are members of the CD20-like family.
The MS4A genes are usually organized in a single genomic clusters in mammals, suggestive of gene duplication events.
[1] MS4A genes encode a class of four-transmembrane spanning proteins.
MS4A genes have been described to act as a specific kind of olfactory receptor in the necklace olfactory sensory neurons in mice (Mus musculus).
[2] In human (Homo sapiens) the members of this family include: