Although Alox15 deletion was previously shown to protect against T1D in NOD mice (19), it has remained unclear if the effect could be attributed to its expression in the islets, myeloid cells, or both, particularly since proinflammatory cytokines and their signaling are affected by the loss of Alox15 in both cell types (30, 41). Here, ALOX15 is linked to type 1 diabetes mellitus.