Expression of E2A is decreased in metastatic CRCs. A, Relative E2A mRNA expression in primary CRCs with or without metastasis. The levels of E2A mRNA were examined using qRT-PCR by the 2-ΔCT method with GAPDH mRNA as internal control. B, E2A protein expression in primary CRCs with or without metastasis was detected with immunoblot using GAPDH protein as loading control. Protein samples of lane 1, 3, 5, 7, 9 and 11 were from tumors without metastasis, while lane 2, 4, 6, 8, 10 and 12 were from tumors with metastasis. Samples were selected and paired randomly. Data represents means ± SD from 3 independent experiments. **, P < 0.01.