CCL2 and preeclampsia: The pro‐ and anti‐inflammatory cytokines play crucial roles in the development and functions of placenta.[31] It is generally agreed that preeclampsia is associated with both local and systemic changes in type 1/type 2 cytokine balance compared to normal pregnancy.[32] To investigate whether this model can shed light on the mechanism of preeclampsia, we detected the levels of inflammation cytokines in the conditioned medium of PVOs using a human inflammation panel that included cytokines such as IL‐1β, TNF‐α, IL‐10, IL‐18, IFN‐γ, IL‐8, IFN‐α2, MCP‐1, IL‐6, and IL‐12.