SOX6 and Parkinson disease: Given the proposed vulnerability of Sox6 + DA neurons and relative resilience of Calb1 + neurons in PD (Gaertner et al., 2022; Kamath et al., 2022; Pereira Luppi et al., 2021), we first compared these two cluster families across Lrrk2 mutants versus control mice to see if any changes in DA neurons are specific to vulnerable or resistant cell types.