PDPN and cancer: PDPN expression on fibroblasts can promote TLS establishment (54), while recent studies in PDAC demonstrated that a PDPN+ CAF subtype (112, 118) was associated with improved prognosis and enrichment of immune-related pathways, However, the role of PDPN in cancer is controversial, and associated with worse outcomes in multiple cancers, including PDAC (119, 120).