CSF2 and congenital rubella syndrome: In addition, purine metabolism (e.g., xanthosine, xanthine, guanosine, adenine, GMP, adenosine, and guanine) exhibited strong correlation with CRS-related cytokines (e.g., IL-6, M-CSF, MCP-3, GM-CSF, IL-1α, and IL-1β) (Fig. 2g).