ACTA1 and neoplasm: CAF heterogeneity refers to the presence of at least two major subtypes of pro‐tumor CAFs: inflammatory CAFs (iCAFs), which express high levels of inflammatory cytokines and chemokines (such as CXC motif chemokine ligand (CXCL)1 and CXCL8 [13]), and myofibroblastic CAFs (myoCAFs), which express high level of α‐SMA in response to TGF‐β signaling [14].