GEM and familial pancreatic carcinoma: Our previous studies showed that orthotopic DT6066 (mouse derived pancreatic cancer cell line) and spontaneous KPC (KrasLSL-G12D/+; p53R172H/+;Pdx1-Cre) tumors were resistant to Gem monotherapy after a long period of treatment, and these treated tumors were highly desmoplastic, demonstrating the regulatory role of pancreatic stellate cells in tumor chemoresistance [31].