CYP1A1 mRNA expression in different drug groups at different time points. Quantitative real-time PCR was used to detect mRNA in the drug and control groups (A: isoniazid, INH, B: pyrazinamide, PZA, C: INH + rifampicin (RIF), D: INH + RIF + PZA). Each group included 6 parallel samples, each of which was measured 3 times.