PDE6B and infection: Of the 77 HRG dogs showing a PPDB-biased response, 62% simultaneously showed a significant response to ESAT-6/CFP-10, which is strongly suggestive of infection with an RD-1+ MTBC organism; this is slightly lower than the proportion reported for both cattle (~75% in the high-specificity IGRA, where both the PPD and peptide must be positive, and 82% for peptide alone as a diagnostic) and cats (80%, but too few cats for significance) [10,50,51].