This gene encodes a specific inhibitor of protein phosphatase-1 (PP1) with a differential sensitivity toward the metal-independent and metal-dependent forms of PP1. The gene is located within the major histocompatibility complex class I region on chromosome 6. [provided by RefSeq, Jul 2008] see less This gene encodes a specific inhibitor of protein phosphatase-1 (PP1) with a differential sensitivity toward the metal-independent and metal-dependent forms of PP1. The gene is located within the major histocompatibility complex class I region on chromosome 6. [provided by RefSeq, Jul 2008]