PP2A is a trimeric enzyme composed of a catalytic C-subunit, a scaffolding A-subunit, and various regulatory B-subunits, which collectively dephosphorylate a vast majority of cellular serine/threonine phosphorylated proteins, including many involved in cancer progression.

CIP2A has been shown to regulate phosphorylation and activity of numerous oncoproteins, promoting malignant cell growth and tumorigenesis in various human cancers.

Importantly, it has been estimated that collectively PP2A complexes can dephosphorylate a vast majority of all cellular serine/threonine phosphorylated proteins including large number of phosphoproteins involved in cancer maintenance and progression.

[8] CIP2A has been shown to regulate phosphorylation and activity of many other oncoproteins and to drive malignant cell growth and tumorigenesis in various human cancer types.

In a recent phosphoproteome study CIP2A depletion was shown to induce dephosphorylation of more than a hundred phosphorylation sites in proteins that were involved in a wide range of cellular functions.

[10] Importantly, CIP2A deficient mice are viable and do not display any life-threatening spontaneous phenotypes,[11] suggesting that targeting of oncogenic function of CIP2A would not result in serious side-effects.