INS and obesity due to melanocortin 4 receptor deficiency: Thus, obesity-induced inflammatory signaling pathways include activation of IκBα kinases (IKK), the c-Jun N-terminal kinases (JNK), atypical protein kinase C (PKC) and it has been recently recognized that altered diacylglycerol (DAG) content in skeletal muscle can induce insulin resistance via diacylglycerol kinase (DGK) activation [27].