TF and cancer: By conjugation with cancer cell targeting biomolecules, such as transferrin (Huang et al., 2013), RGD peptide (Fu et al., 2016), folate (Liu et al., 2015a), and gracilaria lemaneiformis polysaccharide (Jiang et al., 2014), Se NPs could selectively deliver anticancer drugs into cancer cells to achieve enhanced anticancer activity.