In striking contrast, only 10% of DOX-treated TetO-HO-1+ pIi-tTA+ double transgenic mice developed T1D before 9 months of age, compared to 70% of DOX-treated TetO-HO-1+ pIi-tTA− single transgenic mice (Figure 4A). The gene discussed is HMOX1; the disease is type 1 diabetes mellitus.