Interestingly, in a Phase I clinical trial in R/R CD19+ adult B-cell non-Hodgkin lymphoma (NHL), two different cellular products were simultaneously infused in each patient: one transduced with a second-generation CD19 CAR containing one costimulatory domain (CD28) and another with a third-generation CD19 CAR encoding CD28 and 4-1BB costimulatory domains (NCT01853631). Here, CD28 is linked to B-cell non-Hodgkin lymphoma.