MAPK8 and Insulin resistance: Endoplasmic reticulum stress is an important contributor to adipose tissue and hepatic insulin resistance, through multiple mechanisms including (i) activating JNK and p38, (ii) inducing the pseudokinase tribble 3 (TRB3), which prevents insulin-induced Akt phosphorylation, and (iii) upregulating protein tyrosine phosphatase B (PTPB), a negative regulator of the insulin receptor [34, 70, 71].