CD19 and Interstitial pneumonitis: Besides well-known cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome during CAR-T cell therapy, there were several rarely encountered fatal complications.<h4>Case report</h4>A 63-year-old male patient with refractory EBV-positive diffuse large B-cell lymphoma, developed interstitial pneumonitis with prolonged hypoxemia at 16 weeks after CD19 CAR-T cell therapy.