CX3CL1 and neoplasm: As shown in Figure 6A, CX3CL1 concentrations in co-cultured media were 308.42 ± 40.35 pg/mL in the A549 group and 282.66 ± 31.59 pg/mL in the H1975 group, which were both nearly 4-fold those in single VBMEC cultures (76.33 ± 15.02 pg/mL, P < 0.01, P < 0.01), indicating the enhanced effect of tumor cells on CX3CL1 production in VBMECs.