SQSTM1 and Parkinson disease: In LRRK2-PD–derived fibroblasts, one study assessing different LRRK2 mutations (i.e., R1441G, Y1699C, G2019S) showed decreased levels of p62 specifically in R1441G and Y1699C mutant LRRK2-PD–derived fibroblasts [80], while another study including only G2019S-LRRK2 PD patients found increased p62 levels [81].