LRRK2 and Parkinson disease: Interested in LRRK2-mediated immune pathomechanisms, we differentiated in parallel iPS cells reprogrammed from PD patient fibroblasts containing the LRRK2 (G2019S) mutation, iPS cells containing a ZFN-mediated LRRK2 (G2019S) knockin, and the corresponding isogenic control cell lines, into monocytes.