FOLR1 and congenital rubella syndrome: Once we dropped the CAR-T cell dose to ~5–6 million/animal for THP1-FRβ and HOS-FRα studies, EC17 CAM dosing was safer and its tumor uptake more easily modulated to minimize the risk of severe CRS by means of intermittent “on-and-off” and intra-host dose titration (Figures 8, 9).