In the HepG2 cells other modulated genes involved in cell-cycle regulation and proliferation included OKL38, IGFBP1, CTGF and FGG. OKL38, the pregnancy-induced growth factor and IGFBP1, which has been shown to reduce the growth of prostate cancer cells in culture [49] were both induced in response to BaP. Here, CCN2 is linked to prostate cancer.