CXCR2 and colorectal carcinoma: In vivo, the combination of ferroptosis induction by Glutathione peroxidase 4 inhibition (Withaferin A) along with PD-1 and CXCR2 inhibitor (SB225002) a MDSC blocker effective for CRC liver metastasis inhibition (Fig. 3), whereas primary CRC tumor was resistant to this combinatorial treatment [161].