TF and cancer: A classic example of theranostic and its application in cancer medicine is given by Muthu et al [37] where they developed TPGS micelle conjugated with ligand transferrin which mediated co-delivery of therapeutic docetaxel (drug) and diagnostic nanoclusterAuNc (imaging) for simultaneous detection and treatment in transferrin receptor expressing MDA-MB-231-Luc breast cancer in vitro model.