S100A9 and tuberculosis: Quantification of co-expression revealed a significantly elevated expression of Arg-1+ (P = 0.006), Arg-1+MAC387+ (P = 0.002), Arg-1+CD15+ double-positive (P = 0.05), and Arg-1+CD15+MAC387+ triple-positive (P = 0.03) cells in TB/HIV co-infection compared with TB infection (Figure 6, F, J, L and M).