Protein phosphatase 1 regulatory subunit 11, also known as PPP1R11, is a 126 amino acid protein that is expressed in a variety of both adult and fetal tissues. PPP1R11 functions as an inhibitor of PP1 (protein phosphatase 1), specifically exhibiting a sensitivity toward the metal-independent and metal-dependent forms of PP1. Deletion of a portion of the q arm of chromosome 6 is associated with early onset intestinal cancer, suggesting the presence of a cancer susceptibility locus. Recombinant human PPP1R11 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.