SLC18A2 and Parkinson disease: Importantly, joint pattern analysis of multiple tracers represents a new analytical method to identify patterns reflecting functional similarities and differences provided by each tracer, as for 11C-methylphenydate (DAT) and 11C-DTBZ (VMAT2) labeling in early PD [13], revealing a shared pattern of asymmetry, rostro-caudal gradient, and progression of pathology in the least-affected striatum, while DAT appeared relatively more preserved in the posterior putamen.