Moreover, mtDNA copy number analysis also revealed increased levels in LRRK2+/PD+ (median: 19.68, IQR: 7.11–34.77) compared to LRRK2+/PD− fibroblasts (median: 4.98, IQR: 3.32–7.46; Kruskal–Wallis followed by Dunn's tests: p = 0.024) (Figure 2B, Supplementary Table 3). Here, LRRK2 is linked to Parkinson disease.