CD19 and congenital rubella syndrome: Moreover, despite the notable success of CD19 directed CAR T-cells, they face inherent limitations, including dependence on autologous sources, challenges arising due to the emergence of CD19 escape variants, variable duration of persistence within the host, long manufacturing times, and the potential for severe complications like cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) (56, 57).