HK2 and rheumatoid arthritis: Bustamante MF et al may have explained these results by combining overexpressed HK2 with an invasive phenotype in human FLS cell lines.[11] Meanwhile, these data further indicate that HK2 may correlate with the autoimmune response and disease activity of RA, which may help clinicians to assess disease activity and guide treatment before starting a particular therapy particularly in the era of biological drugs.