CXCR4 and HIV infectious disease: Notably, several immune-related genes were significantly upregulated in the RAI subgroup, including CXCR4, CXCL10, CCL5, FCER1G, CD52, and CLEC12A. What worth of noting is that CXCR4 is an important coreceptor for HIV infection, and its increased expression in the RAI subgroup suggests a higher HIV susceptibility in this subgroup.