Multiple bacteriophage systems demonstrate significant potential in vaccine development, targeted drug delivery, and disease diagnosis for breast cancer. Moreover, their ability to directly infect and eliminate pathogenic bacteria also provides unique value for bacteriophage-based therapeutic strategies [180]. For example, Shoae-Hassani et al. developed apoptin-expressing λ phage nanoparticles that target her-2-overexpressing breast cancer cells and significantly inhibit their proliferation in vitro/vivo [181]. The gene discussed is ERBB2; the disease is breast carcinoma.