Conditional ablation of FAP+ HO-1+ TAMs in an immunogenic ovalbumin (OVA)-expressing LL2 tumor, using diphtheria toxin in a bone marrow chimera of a FAP/diphtheria toxin receptor (DTR) transgenic mouse, or pharmacological inhibition of HO-1 with tin mesoporphyrin (SnMP), decreased LL2 and PDAC tumor growth, confirming the pro-tumoral and immunosuppressive role of TAMs-derived HO-1 (51, 55). The gene discussed is HMOX1; the disease is neoplasm.