ALK and neoplasm: In contrast, efficacy is much lower in case of tumors that express low levels of ALK, which is fully coherent with observations that CAR-T cell approaches need a high antigen density on the targets to reach a maximal effect.4 However, this obstacle can be removed through the administration of the ALK inhibitor lorlatinib, which not only reduces tumor growth on its own but also increases surface expression of ALK on the neoplastic cells and thus renders them likewise highly susceptible to the CAR-T cells.