It is possible that αvβ3-MI3-PD NPs had less impact on tumor cell burden as measured by BLI in the 4T1 triple negative breast cancer compared with the ER+ PyMT-Bo1 breast cancer, because there are significantly lower percent of M2-type TAMs in the 4T1 model as compared to the PyMT-Bo1 control tumors. Here, ESR1 is linked to breast cancer.