However, a study conducted by Lin et al. using 127 INH resistant isolates from California, a population which is thought to mirror global MDR-TB diversity due to immigration, identified a global frequency of 61% for katG315, 23% for inhA -15 mutations, and 83% for the cumulative frequency of either mutation, approximating the frequencies of these mutations as quantified in this systematic review [34]. Here, INHA is linked to tuberculosis.