Remarkably, the link between endolysosomal impairment and synaptic dysfunction within PD derives also from these approaches, which have recently confirmed the causal role of several “lysosomal” and “synaptic” genetic hits (i.e., ARSA, CTSB, GALC, IDUA, RAB29, RAB7L1, SH3GL2, SMPD1, STX1B, TMEM175, VAMP42, and ZSWIM7) [333,343,345,346,347,348,349]. The gene discussed is GALC; the disease is Parkinson disease.