found increased expression of SUMO-activating enzyme subunit 1 (SAE1) and ubiquitin like modifier activating enzyme 2 (UBA2) in FLSs and ST of patients with RA, where SAE1/UBA2 regulated the glycolytic pathway and biological functions of the RA FLSs through SUMOylation-mediated PKM2 phosphorylation (123). Here, PKM is linked to rheumatoid arthritis.