FKBP4 act as a regulator of microtubule dynamics by inhibiting MAPT/TAU ability to promote microtubule assembly. FKBP4 may play a role in the intracellular trafficking of heterooligomeric forms of steroid hormone receptors between cytoplasm and nuclear compartments, it also may have a protective role against oxidative stress in mitochondria. The isomerase activity controls neuronal growth cones via regulation of TRPC1 channel opening.