To further address the issues associated withthe ubiquitous expressionof PD-L1 in the body, an IF THEN gate control SynNotch was added tothe PD-L1-targeting system to provide localized targeting specificity.41−43 SynNotch has already demonstrated a variety of uses in immunotherapy.44−48 In our work, a clinically validated CD19 antigen was introducedto express on a subpopulation of MDA-MB-231 breast cancer cells, whichserved as “training centers” to engage SynNotch andinduce PDbody-CAR production in engineered T cells. Here, CD274 is linked to breast cancer.