Importantly, we observed effective and specific tumour cell killing when NALM6 cells and cytotoxic CD8+ T cells were incubated with LC-BiTE (20%) or CL-BiTE (45%), respectively, during a 6-h time course (Fig. 6C). Similarly, we found a potent, differential CL-BiTE-induced killing of high LGR5 expressing NALM6 preB-ALL and LoVo CRC cell lines versus their low LGR5 expressing counterparts (697 and SW480 cell lines) (EV3A,B), as well as between the patient derived pre-ALL models CRH (high LGR5 expressing) and LC2 (low LGR5 expressing) (EV3C). Here, LGR5 is linked to acute lymphoblastic leukemia.