ALDH1A1 and Parkinson disease: For example, DA neurons expressing CALB1 or SLC17A6 tend to be overrepresented in PD, suggesting reduced vulnerability (Yamada et al. 1990; German et al. 1992; Damier et al. 1999; Steinkellner et al. 2022); whereas DA neurons expressing SOX6 or ALDH1A1 tend to be underrepresented implying increased PD-vulnerability (Liu et al. 2014; Pereira Luppi et al. 2021).