Keep MonoMac6 cells (5×10^5 cells/mL) on ice in assay buffer. 2. Add assay buffer with 100 ng/mL MIF (final concentration: 50 ng/mL) or chemokine + 2 mM Ca2+/Mg2+ (final concentration: 1 mM), incubate at 37°C for 30 min. 3. Negative control: incubate cells without stimulus for 30 min at 37°C. 4. Positive control: incubate cells with 3 mM Mg2+ and 1 mM EGTA. 5. Withdraw samples at different times, add to 4% PFA (final concentration: 2%). 6. Wash cells with PBS, incubate with monoclonal antibody 327C (10 µg/mL) for 30 min. 7. Wash cells with PBS, incubate with anti-mouse-IgG FITC conjugate for 30 min. If staining is not clear, repeat the washing and incubation steps. 8. Measure mean fluorescent intensity (MFI) via FACS, correlating with integrin activation. If the results are inconsistent, repeat the measurement steps.