PCSK1 and type 2 diabetes mellitus: After intersection with the 973 ERS related genes, 8 ERS-related DEGs (RTN1, CLGN, PCSK1, IAPP, ILF2, IMPA1, CCDC47, and PTGES3) were screened out as T2DM related ERS-DEGs, which were indicated to be downregulated in diabetic samples (Figures 3C–E).