Finally, five genes were identified to be upregulated in both DLK1−/− and RASGRP1−/− INS-GFP+ cells, four of which have been identified as related or risk genes for diabetes, which highlights the powerful tools to apply isogenic hESCs to dissect the biological functions and molecular mechanism of T1D associated SNPs. Here, DLK1 is linked to type 1 diabetes mellitus.