Recently, structures almost identical to the axonal swellings in En1+/− mice: TH-stained “abnormally large profiles” and “enlarged presynaptic boutons,” were observed in the striata of adult Lmx1a/b conditionally-depleted mice, and they were accompanied by loss of dopamine in the striatum, loss of DNs in SNpc and VTA and other changes resembling both PD and the phenotype of SwissOF1-En1+/− mice29. Here, TH is linked to Parkinson disease.