A study on choroquine effect to the lymphocyte proliferation of BALB/c mice spleen, infected by Lysteria monocytogenes was carried out. Chloroquine, used for curing malaria and rheumatoid arthritis, is known suppressed the imune response. In this study, 70 BALB/c male mice were divided in 3 groups. The first and the second groups consist of 3 subgroups, which each subgroup consisted of 10 mice.…