In a limited subgroup analysis, the differences in Fibrinogen, CRP, IFN-γ, NCAM and Ferritin concentrations between the spinal TB and mechanical back pain groups remained significant when including only individuals confirmed as HIV uninfected (spinal TB n = 11, mechanical back pain n = 12) and individuals without constitutional symptoms (spinal TB n = 11, mechanical back pain n = 15) (Table 6). The gene discussed is IFNG; the disease is tuberculosis.