The large family of phosphoinositide 3-kinase (PI3K) enzymes can be divided into three distinct classes (I, II and III) based on the sequence similarity and lipid products they generate in vitro. In mammalian cells there are three class II PI3K isoforms, and PI3K-C2beta act as downstream targets of growth factor, chemokine and integrin receptors. The proline-rich motifs within the N-terminal region of PI3K-C2beta mediate its association with activated receptor, and the enzyme regulates cell migration, suggesting its potential role in tumour metasthasis. In Drosophila melanogaster, ectopic expression of the enzyme in the larval marginal disks affected the development of the wings, and the number of external sense organs, suggesting a role of the enzyme in the signalling pathways affecting pattering. Furthermore, the enzyme is localized in the nucleus and is activated during G2/M phase of the cell cycle via calpain-mediated proteolysis Enzyme contains nuclear localization sequence within C2 domain, which is crucial for its nuclear localization and translocation.