Early studies revealed that SMAD4 deficiency did not affect normal pancreas development but accelerated PDAC development in combination with KRASG12D mutation, and WT SMAD4 in PDAC facilitated EMT and TGF‐β‐dependent growth.[52] As the dual effect of TGF‐β on cancer development has been well illustrated,[53] we reasoned that SMAD4’s function is also complex depending on multiple factors such as tumor stage, tissue context, and immune microenvironment. Here, SMAD4 is linked to cancer.