IGF1 and metabolic syndrome: Among these pathways, the insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) axis, which is one of the most commonly deregulated signaling pathways contributing to the development of several types of human malignancies including HCC [25,26], seems to be particularly interesting because this axis plays a key role in metabolic syndrome-related liver carcinogenesis [7,8,9], as discussed in the next section.