DDIT4 and Parkinson disease: Specifically, RTP801 was upregulated at both transcriptional and protein level in neuronal PC12 cells treated with PD mimetic toxins 6-OHDA, MPP+ and rotenone, and it was also induced in neurons of MPTP-treated mice and in Substantia Nigra pars compacta (SNpc) degenerating neurons of PD patients.