In 2018, the WHO issued new treatment recommendations for HRRS-TB, replacing 9 months of RIF, ethambutol (EMB, E), and pyrazinamide (PZA, Z) with 6 months of REZ plus levofloxacin (Lfx).11,12 The WHO supports the addition of high-dose INH for strains with inhA but not katG mutations.12 The gene discussed is INHA; the disease is tuberculosis.