<prompt> Azathioprine is used asImmunosuppressantAntigout drugAnti-retro virusAnti- cancer  <response>: CompoundUseNucleoside analogueBromodeoxyuridineaStudy cell proliferationThymidine analogueAllopurinalAnti gout drugHypoxanthine analogueAzathiopineImmunosuppressantPurine analogue 