Indeed, while Rx typically confers ER to PVX in the context of authentic virus infections, isolated and prolonged production of CP, for instance via Agrobacterium-mediated transient expression, does trigger an HR in Rx potato genotypes [8], [9], as seen previously and here upon transient and transgenic expression of P19 in specific Nicotiana species (Figure 1B–C, [56]). The gene discussed is CP; the disease is viral infectious disease.