KLRI2 depends on KLRE1 for cell surface expression in 293T cells. A, Flow cytometry analysis of 293T cells transiently transfected (Tx) with wild-type KLRI2-HA or KLRI2-HA carrying a mutated transmembrane region (KLRI2-HA K95I) either alone or in combination with KLRE1. B, Flow cytometry analysis of 293T cells untransfected or stably transfected with wild-type or mutated KLRI2-HA. EV, Empty vector. Surface expression was detected by anti-rat KLRE1 mAb WEN27 , anti-HA (−), or secondary (sec.) Ab alone .