To investigate whether the upregulation of HO-1 in DCs could impact the development of T1D in NOD mice, we used a pIi-tTA+ transgenic mouse strain in which the tetracycline transactivator (tTA) gene was under the control of the MHC-II invariant chain (Eα-Ii) promoter [16]. Here, HMOX1 is linked to type 1 diabetes mellitus.