Specifically, the protein isoforms from FN1 (P02751-11), TPM3 (P06753-2), TPM1 (P09493-5), and NME2 (P22392-2) displayed a significant decrease in abundance in RA (p < 0.05) and a >1.5-fold decrease (Supplementary Data S4). Here, NME2 is linked to rheumatoid arthritis.