ROR1 and neoplasm: The poor tumor infiltration and low persistence of ROR1 CAR-T cells may be related to the immunosuppressive TME that leads the engineered T-cells to upregulate multiple inhibitory receptors and loss the capacity to produce interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and granulocyte-macrophage colony-stimulating factor (GM-CSF) (130).