ALDH1A1 and Parkinson disease: Consistent with prior reports (Yamada et al., 1990; Pereira Luppi et al., 2021; Del Rey et al., 2024), the number of CALB1+ DA neurons was not significantly affected, though a trend was observed (U=19.5, p=0.08) (Figure S1B–C), while ALDH1A1+ DA neurons were significantly reduced in PD (U=1.0, p<0.0001) (Figure S1E–F).