The inclusion criteria used in special Chapter 3 were as follows: (a) studies showing the effect of flavonoids in the BC; (b) the experimental group was administrated with nanomaterials and any kind of flavonoids; (c) effects of flavonoids were associated with the modulation of NF-κB signaling; (d) studies in vitro, animal, and human using natural or synthetic flavonoids; (e) controlled experiments; (f) studies with pure flavonoids and combination therapies; (g) studies reporting the modulation of cancer cell plasticity and/or overcoming drug chemoresistance by flavonoids via NF-κB signaling. The gene discussed is NFKB1; the disease is breast cancer.