ITIH5 and breast cancer: The extracellular matrix protein ITIH5 has been shown to be a tumour suppressor in many cancer types3–10 where expression is lost likely due to hypermethylation of the promoter.11,12 Compellingly, ITIH5 expression in breast cancer is also found to be associated with a rounded cell morphology13 and decreased metastatic efficacy.14 However, its mechanism of metastasis suppression in PDAC remains unknown.