CD19 car mRNA-LNP, a lipid nanoparticle (LNP) encapsulating CD19 car mRNA, is instrumental in assessing RNA delivery, translation efficacy, and cell viability among other applications. This compound is pivotal for chimeric antigen receptor T cell immunotherapy (CAR-CD19), leveraging the CD19 molecule - a critical membrane antigen expressed by B cells (i.e., leukocyte differentiation antigen) that plays a significant role in their proliferation, differentiation, activation, and antibody production, as well as enhancing BCR signal transduction [1] [2].