HK2 and rheumatoid arthritis: Among them, HK2, which has a high affinity for glucose and contains two catalytic domains, is the main induced isoform.[16] In addition, increased HK2 in fibroblast-like synoviocytes (FLSs) was demonstrated to have a relationship with the aggressive phenotype of RA.[11] However, the role of HK2 in peripheral blood mononuclear cells (PBMCs) of RA has recently been uncovered, and the mechanisms responsible for glucose metabolism in peripheral blood need to be explored in more detail.