IFNG and tuberculosis: A third type of error was recognized for six subjects who had extremely high IFN-γ concentrations reported for TB values in Lab3 (range 37.4 to 102.5 IU/mL) when compared to Lab1 and Lab2 (range 8.6 to 18.4 IU/mL) and when compared to other Lab3 TB values (all >7 times the interquartile range of 3.33 IU/mL).