ACTA1 and cancer: Importantly, by in vitro assay, we confirmed that stimulation with the LLC cancer cells conditioned medium (LLC‐CM) was capable of inducing de novo expression of CAF antigens (α‐SMA, FAP) and effector (vascular endothelial growth factor (VEGF)) in BMDM but not the fibroblasts (Figure 3G; Figure S7, Supporting Information); clearly demonstrating a direct role of MMT in CAF formation.