Mesoporous silica NPs used for delivering a lipid-conjugated IDO inhibitor prodrug plus oxaliplatin caused tumor regression or eradication in a pancreatic ductal adenocarcinoma mouse model, wherein the IDO inhibitor prodrug showed the unexpected benefit of synergistically enhancing the ICD response upon treatment with oxaliplatin [101]. Here, IDO1 is linked to pancreatic ductal adenocarcinoma.