In addition, there were clear differences in the stromal microenvironment of the KP KF tumours, such as a lack of infiltrating alpha-smooth muscle actin (αSMA)-positive stromal cells and low levels of stromal collagen deposition (as indicated by picrosirius red), again, contrasted by KP tumours (Fig. 5i, j). This evidence concerns the gene ACTA1 and neoplasm.