ACTA1 and neoplasm: In Pdx1-Cre; LSL-KrasG12D/+; Trp53flox/flox (PdKP53) mouse models of PDAC, αSMA+ fibroblasts were preferentially located in juxta-tumoral regions, as defined by the expression levels of αSMA within 0–10 μm versus 10–20 μm distance from tumor margins (Fig. 1a–c).