PURPOSE OF REVIEW: In this review, we discuss the most recent developments in 
gene-editing technology and discuss their application to adoptive T cell 
immunotherapy.
RECENT FINDINGS: Engineered T cell therapies targeting cancer antigens have 
demonstrated significant efficacy in specific patient populations. Most 
impressively, CD19-directed chimeric antigen receptor T cells (CART19) have led 
to impressive responses in patients with B-cell leukemia and lymphoma. CTL019, 
or KYMRIAH™ (tisagenlecleucel), a CD19 CAR T cell product developed by Novartis 
and the University of Pennsylvania, was recently approved for clinical use by 
the Food and Drug Administration, representing a landmark in the application of 
adoptive T cell therapies. As CART19 enters routine clinical use, improving the 
efficacy of this exciting platform is the next step in broader application. 
Novel gene-editing technologies like CRISPR-Cas9 allow facile editing of 
specific genes within the genome, generating a powerful platform to further 
optimize the activity of engineered T cells.