Therefore, the aims of thisstudy are (i) to determine the amount and subtypes of FRβ+ myeloid cells infiltrating the tumors at different stages,(ii) to compare the amount and subtype of FRβ+ myeloidcells in distinct organs of tumor-bearing and healthy animals, (iii)to test if the cancer-targeting efficacy and biodistribution of aprototypic folate-functionalized nanoparticle associates with thedensity of FRβ+ myeloid cells. The gene discussed is FOLR2; the disease is cancer.