Since the in vivo data from PD invertebrate model system showed a modulatory effect of ITPKB activity in α-synuclein-dependent pathology, we determined ITPKB levels in human PD cellular model systems, where no data are currently available on the effect that mutations in SNCA gene may have on ITPKB expression or function. The gene discussed is ITPKB; the disease is Parkinson disease.