ZC3H12B, also known as MCPIP2, is a member of a family of novel CCCH-zinc finger proteins that regulate macrophage activation and may be involved in host immunity and inflammatory diseases. The function of ZC3H12B is not well understood. Unlike other members of the ZC3H12 family, ZC3H12B has a RasGEF domain at the C-terminal of the zinc finger motif, suggesting its potential involvement in Ras-mediated signal transduction. It is highly expressed in brain, thymus, and testis, but unlike ZC3H12A and ZC3H12C, not expressed in macrophages after treatment with lipopolysaccharide (LPS).