During the first treatment phase, frequencies of PPD, CFP10 and ESAT6-specific IFN-γ secreting cells were higher in group 1 (HE/HRZ) relative to levels in group 2 (HRZ/HE) (Figure 6A–C), whereas the responses made by the two groups were similar during the second treatment phase. This evidence concerns the gene IFNG and hereditary elliptocytosis.