In the present study, GPC1 was defined as a specific PDAC TAA with the following characteristics: (i) localization on the cell surface [23]; (ii) increased expression in PDAC cells compared to low or absent expression in chronic pancreatitis or normal tissues [18–20]; (iii) interaction with various growth factors involved in cell proliferation, angiogenesis and metastasis [18–21, 39, 40]; (iv) the possibility of modulating the tumor microenvironment and reducing the state of desmoplasia, thanks to its expression on CAF [24]. Here, GPC1 is linked to neoplasm.