LACTB and breast cancer: LACTB is a mammalian protein that contains a domain sequence similar to that of penicillin‐binding proteins and β‐lactamases.[1, 2] A recent study showed that LACTB acts as a tumor suppressor in breast cancer and is involved in regulating lipid metabolism.[3] After that, more scholars explored the LACTB protein and reported that it played a tumor suppressive role in several tumors, including breast cancer, hepatocellular carcinoma, colorectal cancer and glioblastoma.[3, 4, 5, 6, 7, 8] However, Peng et al.