This technology includes the discovery that two specific microRNAs are not required for the development and function of brown fat in mice. Effects of inactivating microRNAs in cell culture in vitro have not always been reproduced in vivo. The paper tests the effect of inactivating two microRNAs, miR-193b and miR-365-1 on the differentiation, function and development of brown adipose tissue. In contrast to positive results previously observed in vitro, the mouse in vivo studies failed to demonstrate significant effects.