The most advanced CAR T cells developed to date are directed against CD19: tisagenlecleucel and axicabtagene ciloleucel, both released onto the market in the United States and Europe in 2017/2018, tisagenlecleucel for use against pediatric B acute lymphoblastic leukemia (B-ALL) and diffuse large B-cell lymphoma (DLBCL) in relapse or refractory to standard immunochemotherapy treatment and axicabtagene ciloleucel for DLBCL only [7]. This evidence concerns the gene CD19 and precursor B-cell acute lymphoblastic leukemia.