Microtubule formation depends both on chaperone-mediated production and assembly of α/β heterodimers and on microtubule-associated proteins. Production of α and β tubulin proteins requires assistance from chaperone proteins. The chaperone prefoldin associates with nascent tubulin polypeptide chains and delivers them to the CCT chaperone. CCT folds them into stable forms, which are delivered to the tubulin cofactors A and B [47]. CoA and CoB both transfer tubulin monomers to the CoC/D/E complex, which assembles the monomers into α/β heterodimers ready for introduction into microtubules. Tubulin reservoirs are held by the microtubule-associated protein stathmin (green box), which, depending on phosphorylation, binds to free tubulin and also destabilizes microtubule polymers. A host of micotubule-associated proteins (green circles) associate with the microtubule and regulate addition and removal of heterodimers from both ends of the microtubule; in some cases, they have been shown to regulate tubulin levels. While MTA therapies like the taxanes and Vinca alkaloids target the equilibrium between α/β tubulin heterodimer and the microtubule polymer, PPARγ inhibitors could be affecting any of the chaperone proteins or one of the microtubule-associated proteins that is involved in control of tubulin levels.