Ecto-TMEM219 was also able to re-establish the physiological expression of Caspase 8 and insulin mRNA in purified human islets upon culture with serum of either T1D or T2D patients in place of regular FBS, and as compared with the serum of healthy subjects (Fig. 3s, t). The gene discussed is CASP8; the disease is type 1 diabetes mellitus.