POSTN and melanoma: POSTN expression is associated with aggressive tumor features, i.e. with poor prognosis and metastatic dissemination, in a variety of cancers, including pancreatic [43], biliary tract [44], colorectal [45], oesophageal [46], head and neck [47], lung [48], breast [49], ovarian [50], and genito‐urinary [51] carcinomas, and melanoma [52].