CISD2 is a zinc finger protein that localizes to the endoplasmic reticulum. The encoded protein binds an iron/sulfur cluster and may be involved in calcium homeostasis. Defects in this gene are a cause of Wolfram syndrome 2 (WFS2).

The mutation disrupted the mRNA splicing by eliminating exon 2, and resulted in the introduction of a premature stop codon. Like wolframin, the CISD2-encoded protein, ERIS (endoplasmic reticulum intermembrane small protein), also localizes to the endoplasmic reticulum.Cisd2 gene is involved in mammalian life span control. In mice, Cisd2 was primarily localized to the mitochondria and associated with the outer mitochondrial membrane. Cisd2-null mice showed early senescence and shortened life span compared to wildtype mice.