LRRK2 and Parkinson disease: Of note, only a total of 13 interactors exhibited the same alteration in LRRK2-PD and sPD (Fig. 3A), in which 9 interactors were down-regulated while 4 interactors were up-regulated, suggesting these LRRK2 interactors were consistently affected during PD progression regardless of the existence of the LRRK2-G2019S mutation.