Figure S4 shows an example of MMR genes expression in PA12. PDAC nuclear immunoreactivity for MMR proteins was observed in all the cases with the exception of case PA13. In this case, a heterogeneous pattern of PMS2 expression was observed: next to the areas with normal nuclear immunoreactivity there were areas where tumor cells showed absence of PMS2 nuclear expression along with cytoplasmatic accumulation of the protein. In the same case, a reduced expression of MSH3 was observed too (Table 1). Here, MSH3 is linked to neoplasm.