At the mRNA level, CXCL16 was expressed at 1.47-fold higher levels in PBMC from RA-risk individuals with arthralgia compared to HC (p = 0.021) (Fig. 3A) in Phase I cohort and positively correlated with the TJC (r = 0.576; p = 0.010), but not with the VAS score (r = 0.126; p = 0.606), ESR (r = − 0.084; p = 0.749) or CRP level (r = 0.018; p = 0.943). The gene discussed is CXCL16; the disease is rheumatoid arthritis.