Natural resistance to infection with diverse pathogens, including some Mycobacterium species, Salmonella typhimurium, and Leishmania donovani, is associated with a protein having glycine at amino acid position 169, within the fourth predicted transmembrane domain (G169 or Gly169). This glycine is evolutionarily conserved in rat, human, rabbit and chicken orthologous proteins. G169 is associated with the G variant of SNP rs47476426 and is found in 129P2/OlaHsd, 129S1/SvImJ, 129S5SvEvBrd, C3H/HeJ and most other strains. Reference strain C57BL/6, and BALB/cJ and FVB/NJ have the A variant of the SNP, coding for aspartic acid at position 169, that causes sensitivity. (J:4762, J:20139, J:35004)