2023; Gorski et al. 2020). However, this study shows that its protective effect in PD might occur independently of classical cell cycle regulation. In contrast, while the abnormal activation of Cyclin D1/E2 in the MPTP‐induced PD model can worsen neuronal damage (X. Zhang et al. 2023), MR analysis indicates that lifelong high expression of CCNE1 is strongly linked to a reduced risk of PD. This evidence concerns the gene CCND1 and Parkinson disease.