TF and breast cancer: In turn, Zhang et al. (2015) found that drug carriers with transferrin (Tf) and ART (HA-MWCNTs/Tf@ART) had higher inhibition efficiency on MCF-7 (human breast cancer) cells than drug carriers with ART (HA-MWCNTs@ART) or ART alone (1–50 μM) during 24–72 h incubation.