CX3CL1 and cancer: Except for BAI1, CD31, and MerTK, the enhanced expression of Axl, Tyro3, Gas6, MFGE8, Stab2, Tim-4, CX3CL1, IDO1, Rac1, and PD-L1 was associated with decreased sensitivity to many drugs, which may partially explain the resistance to chemotherapy in cancers.