Spearman correlation analysis revealed that the correlation of expression between IL2RA and CXCL10 was significant with R = 0.63 and P value <0.0001, indicating their close association and similarity in expression pattern for both LTBI and TB conditions, and therefore inclusion of IL2RA into the diagnostic combination is unlikely to improve the discriminative power of the test any further. The gene discussed is CXCL10; the disease is tuberculosis.