One study utilized CAR-T cells modified to express constitutively active IL-7 receptor and proved that these fourth-generation CAR-T cells against AXL, a receptor tyrosine kinase overexpressed in cancer and implicated in cell growth and survival, enhanced specific tumor lysis and cytokine production of IL-2, IL-4, IL-6, TNF-alpha, and IFN-γ in vivo (Figure 2; Table 1; Table 3) [108,109]. Here, IL2 is linked to neoplasm.