SIK1 and type 2 diabetes mellitus: Next, our results found that Ad-SIK1 administration decreased the elevated hepatic mRNA and protein levels of SREBP-1c, FAS and ACC caused by HFD/STZ-induced T2DM, suggesting that overexpression of SIK1 could suppress hepatic lipogenesis by downregulating SREBP-1c and its downstream gene expression, thus leading to a reduction in the TG synthesis, which was further confirmed by a reduction in hepatic TG content.