CDKN2A and hepatocellular carcinoma: Finally, by IHC, we discovered that the protein of CDKN2A, BIRC5, and SPP1 were upregulated in HCC tissues, while IGF1 was downregulated in HCC tissues compared with the levels in paracarcinoma tissues; by RT‒PCR, we discovered that the mRNA of CDKN2A, BIRC5, and SPP1 were upregulated in HCC tissues, while the mRNA of IGF1 was downregulated in HCC tissues compared with the levels in paracarcinoma tissues.