On the other hand, Bernal-Conde and co-workers (2024) [169] reported that, although NPCs derived from PD-hiPSCs with altered SNCA gene expression (over-expression or knock-out expression) could give rise to TH+ neurons, the transplantation of these progenitor cells into a pre-clinical PD rat model resulted in decreased numbers of TH+ neurons in the transplants, compared to control NPCs. Here, SNCA is linked to Parkinson disease.