To test the latter possibility, we washed stationary phase L. major promastigotes extensively as described for infection assays and then stained the parasites with two different domain-specific mAbs: (i) MBK3, a monoclonal antibody that recognizes the BK epitope (domain D4) of kininogens (HK/LK), and (ii) HKH4, a mAb that recognizes domain D1 of HK/LK [36]. This evidence concerns the gene KNG1 and infection.