CXCR4 and lung cancer: Then, inhibitor of ERK phosphorylation (U0126, 10 μm), inhibitor of Akt phosphorylation (MK‐2206, 1 μM) (Zhang et al., 2015), as well as the specific antagonist of CXCR4 (AMD3100, 1 μM) (Hatse et al., 2002), were added into THP‐1‐CM, and results show that they can all efficiently reverse CM‐increased ERα expression in the lung cancer cells (Fig. 7D).