The higher number of TH‐immunoreactive cells observed in treated THDA cell culture has also been described in diverse animal models of Parkinson's disease (PD), where they show that either 6‐OHDA or MPTP‐lesioned animals treated with L‐Dopa present more TH+ neurons, thus refusing the toxic effect of L‐Dopa in the nigrostriatal population (Datla et al, 2001; Darmopil et al, 2008; DiCaudo et al, 2012). Here, TH is linked to Parkinson disease.