TPX2 is a spindle assembly factor, required for normal assembly of mitotic spindles, for normal assembly of microtubules during apoptosis, and for chromatin and/or kinetochore dependent microtubule nucleation. TPX2 mediates AURKA localization to spindle microtubules, activates AURKA by promoting its autophosphorylation at 'Thr-288', and protects this residue against dephosphorylation.Synonyms: C20orf1, C20orf2, DIL-2, Differentially expressed in cancerous and non-cancerous lung cells 2, HCA519, Hepatocellular carcinoma-associated antigen 519, Restricted expression proliferation-associated protein 100, Targeting protein for Xklp2