ACTA1 and neoplasm: Encouragingly, we found that the accelerated tumor growth (Figure4A), Runx1 expression, MMT and CAF formation (α‐SMA, FAP Figure 4B,C) in the NC‐BMDM group were significantly suppressed in the mice that received Runx1‐silenced BMDMs (siRunx1‐BMDM), revealing the essentialness of macrophage‐specific Runx1 in MMT development.