To investigate the potential role of the IGF signaling pathway in liver cancer, we determined the expression levels of 10 IGF family proteins (IGF-1, IGF-1R, IGF-2, IGF-2R, IGFBP-1, IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-6, and Insulin) in 25 pairs of HCC and adjacent tissues using an IGF-1R antibody array. This evidence concerns the gene IGFBP4 and liver cancer.