HMOX1 and cancer: Only moderate survival prolongation was demonstrated which is attributable to adaptive T cell immunity deficiency in NSG mice which is a key factor affecting cancer immunotherapy efficiency.[17, 33] Collectively, our study demonstrates HO1 inhibitor‐mediated chemo‐sensitization in leukemia cells and HO1 inhibitor‐mediated immune activation of myeloid cells as mechanisms for a combination therapy of T‐hNP/SnMP with DNR (Figure 8d).