Based on expression levels of mRNA, it is not possible to predict changes in sphingomyelin levels, but a decrease in acid sphingomyelinase mRNA expression in tissue from all patient groups related to T1D (newly diagnosed, long standing, antibody-positive, transplantation tissue) compared to controls and T2D patients, is surprising, since decreased levels of acid sphingomyelinase is associated with higher levels of regulatory T cells (26), which is not expected in T1D-related conditions. Here, SMPD1 is linked to type 1 diabetes mellitus.