Cholesterol biosynthesis metabolic pathway is specifically activated in liver metastasis of colorectal cancer. A-E, Quantitative RT-PCR analysis of mRNA levels for cholesterol metabolism-related genes in 17 paired samples from patients diagnosed with primary colorectal cancer and liver metastasis. Primary tumors (PT) and paired liver metastases (LM). Data are shown as mean ± SEM after log transformation (n = 17). Each dot represents the mean of relative mRNA levels (log10) in triplicates for the indicated gene in each tissue sample. F, Free and total cholesterol contents in PT and LM. Data are shown as mean ± SEM (n = 10). G, A schematic diagram depicts the expression changes of key genes involved in cholesterol metabolism in LM versus PT. H-J, Representative immunohistochemistry (IHC) pictures of SREBP2 protein in paired CRC samples of PT and LM (n = 6) (left of H), PT and brain metastases (BM) (n = 7) (left of I), or PT and lymph node metastases (LNM) (n = 5) (left of J). The average IHC scores were shown in right of H-J, data were shown as mean ± SEM. Scale bar, 100 μm. Significance was determined by two-tailed ratio t-test (A-F and right of H-J). *P < 0.05, **P < 0.01, ***P < 0.001, ns, not significant.