This probiotic, created by introducing plasmids into Escherichia coli Nissle (EcN), aims to deliver checkpoint blockade nanobodies directly to tumor sites.643 The probiotic employs a cleavage and release mechanism that relies on the LUXL and 4X174E genes to simultaneously express and release nanobodies resistant to PD-L1 and CTLA-4. This evidence concerns the gene CTLA4 and neoplasm.