IGF1 and hepatocellular carcinoma: In addition, compared with HCC cells treated with sorafenib and IGF-1 alone, p-IGF-1R was decreased significantly in HCC cells pre-treated with IGF-1R inhibitor PPP, and the activation levels of key kinases in PI3K/Akt and Ras/Raf/ERK signaling pathways were also significantly inhibited (**p < 0.01).