IFNG and infection: An important role for early IFNγ secretion and the development of a Th1 response against C. neoformans 52D infection was previously shown in resistant C.B-17 mice (a BALB/c strain congenic for C57BL/6 immunoglobulin heavy chain gene segment), whereas the absence of this response in the C57BL/6 strain correlated with susceptibility (11).