ACTA1 and neoplasm: Perhaps surprisingly, conditional deletion of Col1a1 from α-SMA-positive CAFs (α-SMA-Cre/Col1a1fl/fl) crossed with a KrasG12D/+; Trp53frt/frt; Pdx1-Flp (KPPF) mouse model of pancreatic cancer resulted in reduced fibrosis but more aggressive tumours, lower survival, and myeloid suppression of CD8+ T-cells (Figure 2B) [101].