IFNG and tuberculosis: In contrast to the responses to ESAT-6/CFP-10, the responses of M. bovis-infected deer to Rv3615c only slightly exceeded the pre-infection values, with a maximum detection of TB-positive deer at 15 dpi when 40% of the animals elicited an IFNγ response to the stimulation, similar to that which has been previously reported for cattle [39].