To know if this combinatory modification strategy could be applied to other CARs, we transduced second-generation 19bbzCAR into above-characterized GPC3 iCAR-TCTL and DGK dKO GPC3 iCAR-TCTL-mbIL15, and found signal enhancement and proliferation advantage of the combination of IL-15 expression and DGK disruption in vitro (Extended Data Fig. 10a–e) as well as enhanced T-cell survival and tumour suppressive capability in vivo (Extended Data Fig. 10f–i). Here, IL15 is linked to neoplasm.