LRRK2 and Parkinson disease: Zebrafish knock down models have been previously generated targeting the homologues of other PD-causing genes, including PARKIN[19], [20], PINK1[21], [22], [23], DJ-1[24], [25], and LRRK2[26], [27], while the alpha-synuclein gene has no homologue in zebrafish [28].