Spatial validation through immunofluorescence in tissue sections from four patients in the PUCH-PDAC cohort showed significant co-localization of POSTN and integrin β5 on tumor cell membranes, providing in situ evidence for the functional relevance of the POSTN-ITGAV/ITGB5 axis in PDAC (Figure 10A). Here, POSTN is linked to neoplasm.