CD19 and lymphoma: To untangle these possibilities, a recent study (Stein-Thoeringer et al., in press) [57] followed a large cohort of lymphoma patients receiving second-generation CD19-targeted CAR-T cells in Germany and the U.S. Like previous studies, an association was noted between an exposure to antibiotics prior to CAR-T cell infusion and an increased prevalence of cancer relapse or disease progression and a decrease in overall survival.