ROR1 and neuroblastoma: Compared to the non-cytokine-secreting parental virus C134, C021 significantly enhanced the in vitro cytotoxicity (p < 0.05) of anti-ROR1-CAR-NK cells with increased interferon (IFN)-γ (p < 0.05), granzyme B (p < 0.05), and perforin (p < 0.05) secretion against NB cells.