Screen of 14 CNCs using in vitro luciferase enhancer assay. (A) The University of California Santa Cruz Genome Browser representation of the fibrinogen cluster genomic region (NCBI36/hg18; Chr4: 155 661 000-155 891 000) is shown. The localization of the 14 selected CNCs as well as the fibrinogen genes (FGA, FGB, and FGG) and the nearby genes (PLRG1 and LRAT) present in the syntenic vicinity are schematically represented as well as the regulatory potential and the conservation feature. Luciferase assay was performed for 14 CNCs on 3 cell lines (B) HepG2, (C) Huh7, and (D) HEK-293T in both genomic orientations (+ and − strands). Luciferase activities normalized with a control plasmid (Control) are plotted. The gray dashed line represents a 2-fold threshold above which we consider that the tested sequence shows enhancer activity. Error bars show standard deviation; P values were calculated from experimental data versus values for control plasmid condition (*P < .05, **P < .01, ***P < .001, 2-sided t test, n = 3).