Additionally, the term “chromosome segregation” was enriched in old rats, and the genes were almost upregulated in the o-PF group, such as centromere protein (CENPs), NIMA-related kinase (NEKs) and Pttg1, etc., which indicated the genes related to chromosome segregation might be involved in the progression of PF (Table S4). Here, PTTG1 is linked to pemphigus foliaceus.