Methods capable of spatially resolving single molecules have revealed clustered nanodomains of molecules in the PM of model membranes to prove concept of a polarisation-coupled PAINT microscopy and of the much-discussed GLP-1 receptor in the PM of pancreatic beta cells, to provide a better understanding of the signalling pathways of this critical type-2 diabetes implicated molecule. The gene discussed is GLP1R; the disease is type 2 diabetes mellitus.