In silico mapping of the T-cell epitope repertoires within Dsg3 and Dsg1 suggests that similar peptides from both PV target antigens may be involved in disease progression and the evolution in autoreactive lymphocyte reactivity during the course of disease from one clinical subtype to another (mucosal PV to mucocutaneous PV). The gene discussed is DSG1; the disease is acquired polycythemia vera.