Rigter et al. [54] found two high affinity binding regions for protein-protein interactions using ovine peptide-arrays: (i) sheep-PrP peptides 43–102, including the amino-terminal octarepeats, and (ii) sheep-PrP peptides 134–177 which encompasses most of the scrapie susceptibility-associated polymorphisms in sheep. The gene discussed is PRNP; the disease is scrapie.