In general, the intravenous application of PEI-MNPs to animals with low-grade and persistent inflammation induced the following effects: (i) it changed the iron levels in different organs in a time-dependent manner, (ii) it increased the expression of members of the canonical NF-κB signaling pathway soon after PEI-MNP application and later also that of the non-canonical signaling pathway in the liver of the animals, and (iii) it induced leukopenia and alterations of the red-blood cell parameters. The gene discussed is NFKB1; the disease is Decreased total leukocyte count.