In a recent report, Daniel S. Leventhal and co‐workers engineered a strain of E. coli Nissle (referred to as SYNB1891) to express STING‐agonist cyclic diAMP (CDA) (Figure 7).[61] After intratumoral injection of SYNB1891 in murine tumor, a high‐level expression of CDA in tumor tissue was observed. Here, CDA is linked to neoplasm.