Metallothionein proteins are highly conserved low-molecular-weight cysteine-rich proteins that are induced by and bind to heavy metal ions and have no enzymatic activity. They may play a central role in the regulation of cell growth and differentiation and are involved in spermatogenesis. This gene encodes a metallothionein-like protein which has been shown to be expressed differentially in mouse testis and ovary. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008].