PRDM16, which strongly induces UCP1 expression through forming a transcriptional complex with PGC-1α,(38) is highly expressed in adipose tissues and plays a critical role in their development and differentiation.(39) Given these functions, PRDM16 has also been regarded as a promising target for DM treatment.(39,40) However, such potential may not be directly applicable to classical type I DM, which is typically modeled by high-dose STZ treatment. Here, UCP1 is linked to diabetes mellitus.