CXCL9 and rheumatoid arthritis: Notably, genes such as Clec4e, Ccr5, Cxcr6, Ccr7, Cxcl9, Tlr7, and Nod2 exhibited high correlation coefficients (r = 0.8–1.0) with these cytokines (Figure 8a), indicating that their elevated expression is closely linked to heightened inflammatory responses and may play a critical role in driving RA pathogenesis.