Isopentenyl-diphosphate delta-isomerase 2 (IDI2) is also known as Isopentenyl pyrophosphate isomerase 2 (IPPI2 or IPP isomerase 2),which belongs to the IPP isomerase type 1 family and contains one nudix hydrolase domain. IDI2 catalyzes the 1,3-allylic rearrangement of the homoallylic substrate isopentenyl (IPP) to its highly electrophilic allylic isomer, dimethylallyl diphosphate (DMAPP).Recently, it indicates that, in humans, IDI2 is expressed only in skeletal muscle. Expression constructs of human IDI2 in Saccharomyces cerevisiae can complement isomerase function in an idi1-deficient yeast strain. Both isozymes, IDI1 and IDI2 are localized to the peroxisome by a PTS1-dependent pathway. IDI2 is regulated independently from IDI1, by a mechanism that may involve PPARalpha.