Administration of Zr-CeO inhibits MDSC recruitment and M2-type TAM polarization by dephosphorylating extracellular regulated protein kinases (ERK) and signal transducer and activator of transcription 3 (STAT3), leading to irreversible tumor cell death and increased sensitivity to PD-1 inhibition in renal subcutaneous tumors [51]. Here, STAT3 is linked to neoplasm.