ACTA1 and neoplasm: Also, in accordance with the notion that desmoplastic reaction is a prominent feature of human ICC,32, 33 AKT/Jag1 tumours displayed elevated immunoreactivity for smooth muscle actin (α-SMA) and vimentin (VIM) staining in the stromal cells as well as deposition of collagen fibres, as indicated by Picro Sirius Red staining (Supplementary Figure 4).