PRF1 and tuberculosis: After subtracting the background, levels of ESAT6/CFP10‐specific perforin in TB group (ESAT6: 0.90 ± 0.61 ng/mL, CFP10: 1.71 ± 0.59 ng/mL) were significantly higher than that of control group (ESAT6: 0.17 ± 0.42 ng/mL, CFP10: 0.30 ± 0.46 ng/mL), (P < .001), (Figure 2A).