Recently, in an interesting in vivo generation of CD19-CAR-T cell therapy approach, Agawarl et al. demonstrated that CD4-targeted lentiviral vector (CD4-LV) exhibited faster and superior tumor cell killing compared to CD8-LV alone or as a mixture with CD4-LV, suggesting higher CD4+ CAR-T cell efficacy mainly because CD8+ T cells are more prone to exhaustion [201]. Here, CD4 is linked to neoplasm.