Checkpoint immunotherapy with anti-PD-L1 or combined chemo-immunotherapy with IL-2 and doxorubicin significantly reduced tumor growth as compared with therapy-naive mice (p = 0.00031 and p = 0.00011, respectively), whereas iron supplementation without any therapy led to a significantly faster tumor progression (p = 0.039) for comparison with therapy- and iron-naïve animals. This evidence concerns the gene CD274 and neoplasm.