To better determine the effect of HSA-ATO NPs on tumor hypoxia in a relatively real tumor microenvironment, we established a PDX mouse model of colon cancer, and administrated these mice with PBS (control), HSA, 6 mg/kg atovaquone (equivalent amounts of atovaquone, corrresponding to those of HSA-ATO NPs) and 60 mg/kg atovaquone (dosage to effectively alleviate tumor hypoxia) and HSA-ATO NPs (atovaquone at a dosage of 6 mg/kg) for 7 days. Here, ALB is linked to colonic neoplasm.